grx45

I am looking to put a new engine in my 87 z28 this summer. The lg4 305 is giving out and I would like to upgrade it to a 350. I have a limited budget and am looking to get the most for what I have. I found that the gm goodwrench has 290 hp at the crank with headers. So i figure once in the car that should translate to about 220 at the wheels.
The L98 in the 87 iroc was rated at 225. So I am wondering is that at the wheels or the crank. Which engine would be a better swap. I am keeping it carberated and am not to concerned with emissions since it will be historic in a few more years.

NemeSS-TyranT

iTrader: (1)

C. none of the above.

look for a 350 vortec motor. u have few months left.
will find one by then. also i have used the pro products vortec intake
like 100$ and work very well.

grx45

I thought about going the vortec route since they make much better power. How ever they seem to be well out of my price range. The two motors I listed go for around $2500 complete with everything where the vortec equipped engines seem to go for 4K.

My plan for this car is to get a reliable 350 that i can easily drop yet still have good horse power and torque, and that i can commute to college in for three more years. By the time I am out of college it will be old enough to be registered as historic in NJ. At which point it will be come my second car not a daily driver and then i can do more radical things to the engine. And not have any emissions concerns.

So I am basically looking to see how I can get the most power some where between 2-4k. Without having to completely rebuild an engine. That will come down the road.

NemeSS-TyranT

iTrader: (1)

if thats the case, just build a regular 350 with vortec heads and intake.
doesnt necsarily have to be a vortec engine. find good ole 350, and bolt some vortec heads, and a well tuned carb. plenty of tq and power for commuter car.
when u do get out of school.
build a killer LSx motor.

Rich2279

iTrader: (7)

I would make sure that the Goodwrench isn't the one made for pre'86 cars. '86-'87 have different cylinder heads (centerbolt style). This may/maynot matter, just thought I would throw it out there.

Atilla the Fun

The 290 horse 350 is like $300-400 more than the Goodwrench 350, and the only difference, aside from price, and the stickers on the valve covers, is the cam. That's a rather high price to pay for a not very good cam. The price difference is straight profit for GM. And while GM claims 8.5:1, they're both actually just under 8.0:1. Not good, even at sea level, and even worse if you live at higher elevation.
A better course is to find a good used Vortec 350, '96-up, and go from there. They're going for around $500, and they typically don't show any bore wear even at 150,000 miles.
Add an intake, cam and valvesprings and hello 400 horses.

grx45

So from what I understand so far is that the good wrench is 86 and earlier. So that means i need a flex plate to convert the two peice rear main seal to fit my 87 camaro. Also the cylinder heads have a different bolt pattern this i never knew about. Would I be able to add vortec heads to it at a latter date or is the bolt pattern going to prevent that.
Also is the base good wrench the same as the 290 minus the cam. If thats the case would i be better buying the base model and putting in a hotter cam. If thats the case can a better cam on the base good wrench put it past 290 hp?
Finding a vortec engine sounds good but my dad is leaning towards a brand a new crate engine since it will have no wear and tear on it.

Atilla the Fun

Get a flywheel or flexplate for, say, an '84 Camaro, and that solves that. It'll bolt to the new Goodwrench 350, your starter and torque converter or clutch will attach to that.
Heads: The intake manifold bolt holes are different, but that won't stop you from later swapping to vortec heads.
Cam: Buy the base Goodwrench 350, then add a COMP CAMS DualEnergy 275. That will put you past the 290 hp 350.
I'd top it with a Weiand 8501 intake manifold. With headers and exhaust, that'll put you well past 300 hp. But you can't put a Q-Jet on that intake.

grx45

Thanks all this advice has been very useful. I would have never picked up on the fact that the 290 is the same as the base with a different cam on my own.

So the flex plate i never thought about it but I can get that from a salvage yard from an 82-86 camaro and that should attach to a two piece main seal.

The intake i planed to put a new one on and get a new carb since the quadjet has seen better days.

For exhaust i was thinking of putting on headman headers since they seem to be the best for the money right now.

Atilla the Fun

That's what I thought when I bought those Hedman shortys and y-pipe. They suck. Better to Go with Hooker 2055s or MAC Performance.

grx45

The hooker 2055s are better but at 600 dollars more they are out of my budget. I figure the hedman should be good for about four years. And they must be better than the stock exhaust manifolds that are on the third gens anyway.

grx45

So I ended up going to the junkyard and getting a 350 from a 76 c10. I deasembled it only to find out how bad of shape it was in. It looks like the oil was rarely ever changed. The cylyder heads are the ones that are prone to cracking. The is a huge amount of wear on the cam.

Due to all this i am putting all new parts into it. It is currently are no limit speed shop getting manga fluxed and bored 30 over. I am going to put an eagle cast crank and forged i beam rods. With an edelbrock top end kit that includes an perfomer air gap intake and rpm cylinder heads.

I know i will need a new flex plate. Does anyone know what size it is a 158 or 168 tooth.

1bdbrd

iTrader: (1)

Since its a 2 piece rear main, I would say its a 168 tooth but I am not completely sure on that.

What are your plans for exhaust? I saw you mentioned hedman shorties and I figured I would toss in that I have a set for sale for cheap if you wanted them.

Any more info about that top end kit? Are they the aluminum heads and what size is the cam? Sounds like it might be a pretty stout setup..

grx45

The top end kit I am getting is this one from edelbrock.

http://www.summitracing.com/parts/EDL-2098/

It seems to have good heads at least as good as vortechs probly a little better and comes with the performer rpm air gap which seems to be the best choice of intakes from my research so far.

I was going to build the engine myself with my dad. However a friend of a friend happens to be an engine builder and is going to build it for 250. It seems like a good idea because i will then have time to get it in before summer is over and school starts as opposed to if i build it myself. And he routinely builds engines over 600 hp so i think he really knows what he is doing.

I printed out a bunch of papers of possible top end set ups and he suggested that the edelbrock one was the best. Also the most expensive but i figure i want to do it right the first time.

as for the exhaust im just going with the cheapest flowtech headers that bolt right up to the existing stock exhaust. Because i am already going over my budget. they seem to be the cheapes around 129

1bdbrd

iTrader: (1)

Just to let you know, those flowtechs are going to KILL the power that engine can make. The headers I have aren't a whole lot more than the flowtechs are and will be MUCH better for performance.

Also, I don't think the flowtechs bolt up to the stock y. I believe you have to get their y pipe on top of the header price.