Irish-Z

Here it goes...

bought a 91 Z28 with a 305 TPI, and I automatically hate this engine. Im shopping around junkyards and showrooms for a 396 or a 402...same thing really, as I love the engine. (I dont feel like dropping in the 383, seems like the norm, and Im not going to build up a 305.)

So, I basically need help here...maybe someone has done this before? I dont know how im going to wire it, what kind of manual tranny's I should mount (The 402 im looking at was mated to a muncie 4 speed, but the tranny was sold already) and anything else anyone would reccomend...maybe a guide or something?

This will be my first real engine swap, haha, so yeah. help me out.

Its an L34 402 pulled out of a 1970 chevelle...any pointers?

onefast85

buy some hooker swap headers and use the 305 motor mounts.when i done this a while back i hood to some trimming and beating to get them to fit right.

biggest problem was the a/c core which i had to remove for the tall valvecovers.

greezemonkey on here has a a/c delete heater box on his car and i wished i would have had one so i could have still had a heater.

five7kid

iTrader: (14)

Right now you have the engine to hate. As you progress through this swap and get to the emissions portion of the registration, you'll have yourself to hate.

Assuming this is intended to be a street driven car.

If they don't open the hood for the emissions testing in your area, you might have a chance. For the extra weight of the big block, you have to make more power to get the same performance out of the car - possible, but makes getting past emissions testing just that much harder.

I have a 396 in my car because I had a 396 in my garage. I've even speculated about putting it in the Camaro if something bigger goes into the '57 (seach on the carb board if you're interested). However, if I didn't have a BBC and wanted to put a BBC into something, I wouldn't settle for a 396 or 402. 454's have so much more power, and parts for them are typically cheaper than for 396/402. If you think the 454 has too much power for what you want, then you don't want a 396/402, either - SBC makes so much more sense.

383 isn't the only "big" SBC out there. 406's will out-perform a 396/402, just on the basis of weight.

Irish-Z

Extremely interesting.

Problem with the 454 is that its an even bigger block...To get the performance out of it worth having (if you got yerself a 454, you gotta get it to push atleast 450 horsepower...haha, or i would, anyway) but im afraid that the 454 would pretty much twist the camaro in two. (they didnt factory drop 454's in camaros in '67, and the chassis didnt get any bulkier)

I'd like to hear more about that 406, if you dont mind educating me a little. Around here, the kids who actually own V8 camaros either just bolt on a K&N typhoon intake and a flowmaster exhaust, or the ambitious ones stroke the 350 into a 383...I want something thats gonna get me running somewhere in the low 13's at the tracks (granted it will obviously need some work) but the 454 sounds like a major hassle.

And yes, i do hope to use this as a streetcar.

tommyt

The 454 is a BBC just like the 402/396.
They are the same thing externally, and You are looking at the same hassles in swapping in either BBC, with the 396 being at a disadvantage because of its smaller displacement, therefore less streetable power with pretty much identical weight to the 454 and bigger BBC motors. A 406 SBC equipped car would be faster then a 396 car because it will make near the same power NA as the 396, but less weight in the car to carry and accelerate. So, I would argue that Your best bet would be a 406, it will make
400HP NA in a streetable package (maybee not smog-legal, but more so then the BBC), can support in excess of 600HP with spray or forced induction. It all depends on what You want, but up to 400-450 NA HP the
SBC would have the advantage, I think.
No matter which motor You have, the chassis needs reinforcement anyhow... However, if You already have the 402, then You can use it to do the swap, and maybee make it easy to move up to a bigger motor later...

Irish-Z

I grabbed the engine because it was a good deal, but I think Im gonna drop it into something else now... (my best friend wants it for an 80's el camino...

But yeah. I mean, is the 383 the best way to go about it these days? and where would u suggest nabbing a 406?

tommyt

If Your car has a 305, and You stated that You dont want to build that up, then You have to buy a new block either way, and this way getting a 400 block wont be much more expensive then doing a 383, since You need to get a block and rotating assembly for both, and the other parts, like heads, will cost the same either way.
You could look for a 400 in junkyards, You may find one if You are lucky, but I would just look everywhere, shops, friends, friends of friends, maybee even ebay. I picked up a good standard bore 400 block (2 bolt main , supposedly the best for buildups) on ebay for $300. It needs to be machined etc, but I think it was a good deal, since its all good, no damage, no ridges etc, and would clean up with a .020 overbore. There are some around, just have to be patient. Get the 2 bolt block if You can, they are supposedly less crack-prone then the 4bolts. If Your budget allows, You can get an aftermarket block, or a whole aftermarket motor even, they would be the strongest but pretty expensive, and I would argue, overkill for a 13 sec. car.

onefast85

the 454 wasn't a production motor until 1970...thats why they were not in 67 to 69 camaros.my 68 has a 1400hp blown bbc in it and the frame is plenty stout.way stouter than my 85 model.

Air_Adam

They didnt have the 454 in the 1stgen Camaros for two reasons:

1) It didnt exist yet

2) GM execs had a rule about nothing over 400" in a small or midsize car (ie. Nova, Camaro, Chevelle) untill 1970. This is why the biggest "official" engine was the 396, and why the 427 cars were backdoor-specials.

Most people don't know this, but the LS6 (454-450hp) was an option on the '70 Super Sport Camaro. It was on the RPO sheets for awhile, and then dropped, because only one car was ordered and it was too expensive. That car is being restored right now actually. Its a hideous green color.

-------------------------
-------------------------

Now... back on topic.... The 454 block is exactly the same weight as a 427, or a 396/402. They are all BBC engines, and they all weigh the same.

If you want to limit yourself to only 396ci, then IMO, you are missing out. And a 454 is probably easier to find anyway.

Between the 396 big block and 400sbc though, I would take the big block if you can handle the swap issues. I say this, basically just because it would be easier to get XXX horsepower from a 396 than the same amount of power from a 400sbc, just because big block parts are better suited to that kind of cubic inches and the needed breathing capacity. The heads breathe better, the headers are bigger, the intakes are better, etc.

ljnowell

I dont want to throw a BS flag, but I dont agree with this at all. No matter the bore spacing or the amount of iron around the cylinders, the 400sbc will make the power just as easy as the 396 will. Not stock, of course, because the 400 heads suck. But when you cross into the world of a performance engine, they are equally suited to the task. You wont use stock heads anyway. You wont use a stock intake anyway. You wont use a stock cam anyway. In a thirdgen, I would go the 400sb before i would almost any big block. If it was a muscle car I was working on, I wouldnt even waste my time with a 396, I would go strait for the 454.

Irish-Z

And that, my friends, is why you shouldnt drink and type.(referring to my 454 in the 68 camaro folly, although I never understood GM's over 400 rule, considering to bypass it, they just shipped off a few camaros, novas and chevelles off to Yenko and had 427s dropped in em...)

I mean, how insanely hard is it to get these engines to pass an emissions test these days? (granted im not living in california, thank ***) And will the carb, air filter, headers and heads fit under the hood without hardcore modifications to the engine bay?

The more I talk to ya guys, the more Im understanding why so few people go for the killer sized engines...but im still hell bent on trying something!

nsimmons

If the engine isnt super radical and tuned properly it will pass no problems. Engine size plays little in emissions. They test for parts per million, so what if theres 1 million parts or 100 million parts, the ratio stays the same. Case in point, the local standards are actually more strict with an 85 5.0l camaro over an 85 4 cylinder.

My car hardly registers at all as compared to the 4 cylinder or 6 cylinder standards.

five7kid

iTrader: (14)

As for which will make more power, a 400-ish BBC or a 400-ish SBC, I'd have to go with the BB in that contest. Assuming you don't have peanut heads, that is.

Those ports on my 396 are huge compared to the typical SBC head. I've never had them flowed, but this is one case where intuition can be trusted. It was seeing those ports stare at me for a year while the engine was on the stand with wiped out bearings that lead me to fix the thing up and get it going again. Having ported both SBC and those heads, there's just no comparison. However, it has to make more power to make up for its extra weight, hence my earlier statement about why the SBC would be preferred.

As for emissions, check with your local authorities. In Colorado, for example, it is vehicle year, not engine size that matters (see, size doesn't matter after all...). In fact, the standards for the '82 chassis are looser than the '86 engine, but somehow they didn't take note of the fact that it's an '86 engine - their VIN scan just says (1982 2.8l), and that's all they care about it. Only after the mods was it clean enough to pass the '86 standards, interestingly enough. So, before you go slapping in what sounds cool, make sure you know what you're up against.

Air_Adam

This is exactly the kind of thing I was getting at. The basic BBC design will work with 400ci (+/-) better than the SBC design will. The head design, like Five7 described, is a perfect example of what I was talking about.

ljnowell

When focusing on STOCK heads, yes. But why would anyone use stock 400 heads in the first place. I think that if you are going to be comparing its only fair to exlcude those 180hp limiters they called heads that came on the 400sbc stock.

five7kid

iTrader: (14)

Put whatever factory head you want on the SBC 400.

If you say, "Why bother with factory heads? The aftermarket makes great heads," the same applies to the BBC.

However, the weight penalty still applies, so the lesser output of the SBC will overcome the higher flywheel output of the BBC.

Irish-Z

this is awesome feedback.

More questions...

My best friend, whos going to be working with me is extremely familiar with the 454 block, and in my area they are pretty common to find laying around, apparently.

I have never worked on a block bigger than a 350.

Obviously, im going to need to get new motor mounts, and I planned on redoing the exhaust and headers anyway. Will the carb, air filter, headers, all fit under a stock hood, and will I need to make any other modifications to the engine bay?

Also, will the 454's wiring harness mount up at all to a 3rd gen?

As far as tranny's go, my favorite and most familiar is a richmond 5 speed. Can I mount this transmission to the block, and will the shifter fit correctly in the interior console?

lots of Q's for ya guys...this is why Im beginning to love this site...you guys rock! :hail: :hail: :hail:

ljnowell

On the same note, if you limit the 400 to stock heads, you may as well compare it to a 350 instead of a big block, cause the 350 still makes more power.

five7kid

iTrader: (14)

I don't think anybody was advocating factory 400 heads.

Wiring harness will probably work for the "basics" - ignition power, alternator hook-up, gages, electric choke, etc. Transmission/bellhousing mount exactly the same for SBC's and BBC's. Motor mounts are the same, although new replacements would be a good idea.

Carb height, header interference, are issues that always come up with BBC swaps into 3rd gens.

Z28ricer

iTrader: (2)

If you want big cubes, power, and ability to do it reasonably, start looking at the gen 3 engines, a stock 6.0 liter 364 ci can be found easily, as well as just the block from it with an aftermarket rotating assembly coming in at 408 ci with no trouble, heads that flow like crazy stock, and even meaner ported, an 8 coil ignition setup, edelbrock and gmpp both make the carb'd intake since you are wanting to go that route.

ljnowell

Actually that is exactly what I have been looking at for a "next time" project. I have been researching on the net and seeing lots of guys making in excess of 400hp for under 3k, without a lot of effort. But the longblock with ignition coils. Buy the edelbrock kit. New cam and springs, and you have 400+ HP. Seems like a good deal to me.

Z28ricer

iTrader: (2)

Take a look at the gmpp manifold its a single plane compared to the dual plane edelbrock, the MSD ignition box is available seperately. Both combined are about the same $ as the edelbrock kit.

Intake: http://www.paceparts.com/index.asp?P...D&ProdID=18100

Ignition box: http://store.summitracing.com/defaul...h&Ntt=MSD-6010


I've got the 4.8 version of the gen 3 along with a T56 from an f body for my next swap, just gathering up the parts, after i swap it i'll just change the longblock for a 6.0

It pretty much seems like a dumb idea to go out and buy / build a gen 1 when the options with gen 3 are so viable.

BTW thunderracing has a LS1 dyno on their page of a stock headed motor with boltons and their TREX cam making 451 rwhp......

z92maroman

One point I haven't seen mentioned is what the extra weight will do to your handling. You have an awesome handling car in your '91, especially w/some good mods. Putting a heavy BBC in is gonna ruin the weight balance!(which is allready the biggest prob w/handling on 3rdgens) Years ago I built a 350hp 327 vega, and what a mess. It was hell on wheels staightline, but if it even saw a corner, forget it. Massive nose dive to the outside... And this was w/v8 monza springs, hi-press. adjustable gas shocks, poly bushings, the works. IMO you'll be much happier all round by going w/a stout sbc. Good luck

runnriottt

I am glad there are people swaping bb chevys in newer cars out there. Music to a bbc fan. Having two 454's w/ trannys laying around, plus finding a great deal on a third gen, peaked my intrest. I also have questions.
Having transplanted the heart of my Chevelle, from 307 to 454, I am not a total rookie. But there is a ton of room in that ride, they came w/ bb from the plant. This third gen will be a little harder. I have read in an earlyer post 305 mounts work. cool. What about the trans? Are there after market prefab mounts for TH400?
Then the springs. I personaly dont care about a lateral G, so just support is all i want. Are there bb springs for 3rd gen? Who makes em?
Are there anyproblems running the stock fuel tank?
What about the rear? Z28 rear end good enough?
Lastly, the twisting its self in knots post.. The 454's I have are from 1 ton trucks. Lots of torque. What parts are recommended for the frame?
Im looking for stoplight to stoplight, mustang slaying, tire shreder with lots of torqe from a more modern platform. 60's muscle is great, but dosent blend in well. I see lots of exaust up grades, but no swap kits. Any help would be great. Thanks.

booboosean

I am currently working on an '89 that I'm putting a 396 in with a Turbo 400. The small block mounts worked perfectly. I did install some Energy Suspension polyeurethane motor mount inserts. I installed a Spohn Performance Transmission crossmember for the Turbo 400; however, if you wanted to use the stock transmission, you can use the stock crossmember. I have a Currie 9-inch on the way.
I had a friend with an '83 he put a strong small block 400 in and proceeded to break the car in half. So I ordered the complete South Side Machine Lift bar system with the weld-in subframe connectors. Three hours of welding later, and they are part of the car.

onefast85

moroso makes trick springs for a 3rd gen bb camaro
i have a stock tank in my 8 sec camaro.
the rear will hold for a little while,but if you put sticky tires on it you will be upgrading it soon.
truck 454's have peanut port heads and run out of air before 5000rpm.find a set of 781 or 049 casting oval port heads and it will run much better.

good luck

runnriottt

Great info. Talk about bang for the buck! Its looking to me like this isnt going to be a huge wallet wallop. looks like complete swap for around 2 grand complete. have to do some diggin, some ebaying, but this looks totaly posible for a modest investment. Again, thanks for the advice, ill be posting pics as the swap goes in to gear.

booboosean

Hey guys, I noticed this string has stopped, I hope temporarily because originally, it was started by IrishZ who was swapping in a big block. No offense to anyone, but there are obviously a lot of non-big block people out there. IrishZ, if your still keeping up with this, please continue to post information.
I've read so many problems that people have had swapping in a big block and haven't encountered any of them yet. I heard extensive firewall mods had to be made to use an HEI. I bought a brand new HEI from Pro-Form, removed the cap and rotor button, and it dropped right in with plenty of clearance. A tall deck block might cause the lip above the distributor to be notched, but no big deal.
For you guys swapping in a big block, keep the information comming. I'll post new things I come across that I think may be helpful.

onefast85

tall decks fit just as easy,you just have to have custom headers built.here is mine.i have not notched or beat the firewall at all.

booboosean

That's good to know. My next motor will be a tall deck--they are plentiful and practically bullteproof. Yours looks great sitting in there, especially with that Dominator sitting on top. My setup won't be quite that radical. This may be a stupid question, but is that street driven?

onefast85

yes it is street driven a little.i keep it tagged and inspected for those days i want to cruise uptown.

five7kid

iTrader: (14)

I'm not sure exactly what you mean by that - people that don't have or don't know about BBC's; or people that don't like them.

In the case of this thread, I don't think either are the case. Since the originator does not currently have the engine he's going to swap in, it makes sense to carefully consider what you spend your money on before you've spent it. He was looking at a 402 BBC, and all I was saying was that may not be the best choice if you haven't yet plunked down the dough. There certainly would be fewer issues putting in a big inch SBC than there would be putting in a small inch BBC, and the results would favor the SBC. If you're considering a BBC that you currently don't have, consider something bigger than a 402. That's my message.

BTW, there are reasons for some things being the "norm".

booboosean

I knew someone would take that comment the wrong way. Sorry.
I was hoping to expand on this forum so that we could share information on installing a BBC in a 3rd Gen car.
I have run a few 396's in other cars, the one I currently have has a mild hydraulic cam (532 lift on intake and exhaust) and dyno'd at 508 hp (6200 RPM) and 490 foot pounds of torque. That is with a large oval port GM head. We found the small displacement BB Chevys (396-427) respond well without the need for huge intake ports. As the displacement increases, so do the air requirements. No matter which BBC one builds, the horsepower is in the heads and how well they are matched to the engine's displacement. With the prices of aftermarket cranks, heads and rods coming down, the "little" big blocks are becoming less popular. Even so, they are still out there and their perception makes them cheap to some people and, I believe (opinion) they make good solid foundation for a performance build.

greezemonkey

iTrader: (14)

Anything less than 500 cubes is just a baby by todays standards. Get the most for your money! and cubes = torque... the more the better. I know even with a .100 454 that`s mildly radical I don`t even come close to carring a big stick in my neck of the woods..these jokers around here are running with 502`s 540`s and I know of one guy that`s running a 632 in his chevelle all "street cars". I side with five7kid, don`t play with the baby big blocks just get a big small block and save yourself some money and unnessasary pain. My 408 SB ran just a tad slower than my first 454, they both had world heads and similar mods, with about the same amount of $ into each one. 408 ran 12.6 at 115mph w/3.27 rear 230/.500 lift and the 454 ran 12.6 116 out of the gate w/ 3.27 with 244/.580 lift cam. The bigger engine asked for alot more cam and eventually responded with a 11.90 run w/ a 260/630 lift cam..barely streetable though

five7kid

iTrader: (14)

Since emissions were mentioned, I assume this is intended primarily as a driver. Getting nuts with the displacement can lead to heartache down the road (so to speak).

I'll agree that the small inch BBC's can be made to run. I've barely started with mine. However, that's in a 3700 lb w/o driver shoebox, not a 3rd gen. As if we don't have enough problems with weight distribution in 3rd gens already (the front axle weight of my Camaro is very close to that of the '57, if you can believe that). The typical BBC aluminum head is intended for 454+ cubes, so that doesn't make them very friendly for a street driven small inch BBC 3rd gen to solve that problem.

The 402's weren't the greatest castings, either. I can punch my 396 out more than you can a 402.

I guess the originator does have the 402 now, afterall. Hopefully the buddy will come through.

Best 383 source? Gads, they're all over. I know this guy http://feedback.ebay.com/ebaymotors/...413309&frm=284 , he builds 383's, he's doing my 350 shortblock machine work right now. I'm sure he'd do you right if you called him up.

booboosean

I didn't mean to get off topic and debate BB displacement. Sometimes I have to stand back and say, "We're all car guys and best of all Chevy guys." The cool thing about building street rods is doing what you like and being different. Shock value means a lot to some people like lifting the hood on a 3rd gen and seeing a big block is very impressive and makes the car more unique. A friend of mine has a 66 Plymouth with a Hemi and when the hood is lifted and people get a look at that elephant, it gets them talking about cars. My little 396 will push my car into the 11s (if my math is right) and with some nitrous, 10s are conceivable. A lot of people try to be the fastest, but there's an old saying that goes back to the 50s, "There's always somebody faster." If any of you have any more problems you have come across with innovative solutions, pass them on, I'll be reading.

five7kid

iTrader: (14)

Not like I haven't considered it myself https://www.thirdgen.org/techbb2/sho...hreadid=245077 .

rjmcgee

Not that I want a BBC, but what is the weight differance with aluminum heads, intake, and other stuff like water pump over a iron headed SBC? Got to be able to get the BBC down to a resonable weight and not affect handling to bad.

Air_Adam

Actually, if the BBC has aluminum heads, intake, etc... then its not much different than an all iron SBC.

booboosean

A small block Chevy with iron heads and an aluminum intake w/o accessories or water pump is 470 lbs. A big block Chevy with iron heads and an aluminum intake w/o accessories or water pump is 610 lbs. I know aluminum heads would help bring the weight down, (maybe a 60 lb weight savings).

greezemonkey

iTrader: (14)

have you ever lifted a BBC head? more like 60 # a side I`m thinking

five7kid

iTrader: (14)

Going from 350/TH350 and stock radiator, headers, cast iron intake, etc., in the '57 to 396/TH400, aluminum radiator, aluminum intake, headers, increased the overall weight of the car by 70 pounds.

Having bent over the fenders to remove and install those heads once, that was enough for me (or, my back).

booboosean

Yeah, if you think about it, there's not really a whole lot of difference in the weight of the engines when you start considering moving the battery to the back, aluminum parts etc. I do agree the heads weigh a lot and yes, I HAVE lifted a BB Chevy head, probably about 500 times in my life. I've heard the argument from SB people about the weight, but the physical size is harder to overcome in some aspects, especially as it applies to a 3rd gen (which never came with a BB as you all know). All previous gens of the F-body were available at one time with a BB. Choice of parts such as headers are limited. Is Hooker the only Co. that makes these?

greezemonkey

iTrader: (14)

No they are not...there are others but they require mods to the frame fender wells and such. The hookers are supposed to fit but they too require clearencing on odd parts of the frame and body.
Ed Quay, Lemons,Kooks are few that make headers but most are made with such big primary`s that they would only work with a strip only car or a huge by huge engine.

My Merlin heads gotta be 20 #`s more than a stock big block

booboosean

That's what I was afraid of. Guess I'll get the Hookers. At least they aren't outrageous expensive. I hope they clear my SFCs where the collectors come out. Had any experience with that?

Maybe you could port those Merlins. Think you could remove 20 lbs of material from those intake ports? (just kidding)

greezemonkey

iTrader: (14)

The only frame connectors that`ll work would be the alston style, where the connect at the trans crossmember area and go back to the LCA mounts..perimeter one will for sure give you many issues.

I think I could get 10#`s outta each one but the ports are already 325..alot for a street car...I just need to rob a bank to get some aluminum ones now

Here`s a picture if it`ll help you

booboosean

Good picture. My SFCs run on the inside of the rocker panel and are stitch welded the entire length, but they are pretty thin. I don't know if you've heard of them before (South Side Machine) but they work with a crossmember and lift bars that eliminate the torque arm---all in all, a pretty well engineered kit. Can you estimate the gap between the end of your collector and the floor pan? It looks like it may clear.

greezemonkey

iTrader: (14)

well, without looking 1/2- 3/4 of an inch. I can tell you the super comps have the collector "fixed" you cannot rotate it to gain any clearence and they put two holes near the bottom and one straight 12:00 (up). Merlin cyl have a raised port I believe, so leaves less room. I have seen some that hang alot lower than mine.
I trimmed the top of it to clear my floor so it wouldn`t rattle omly half of that 3/8 hole remains up there. I`d cut off the flanges and run a band clamp to make more room, that`ll get you closer

SSC

Well heres a question. Ive read in this fourm poeple have issues with the PS pump hitting the gear box. Is that true? My brackets are 2 one peice units from the vortec 454 truck, any issues there? I should have had them on when I did the mock up install but I never gave the brackets much thought.

greezemonkey

iTrader: (14)

yes I ran into that...I modified an 84 s-10 remote pump and bracket, it has a 4 inch pulley and adapted fairly easily



check the domain site there are afew other pictures of it there, here is just the bracket