Jammin'Trey

Do you guys think its worth my time and money to swap my 2.8L MPFi V6 to a 350 or a 305? I know my Borg Warner T5 isn't going to take a lot of abuse but would a 305 be too hard on it? I am not sure what to do but this 3.8 is a real pooch.... I am looking for around 250 ponies... If i went with a 350 it wouldn't be built or modified in any way (besides a good set of headers and cat back).

Thanks in advance.

p.s. I really wan to keep my T5, I really like the 5 speed. A t56 would be cool too but I dont know if that will drop right in. My upper radiator hose comes out on the passenger side too. (uhh).

PhantomFE3

a 250 horse motor should do fine in front of a T5, but i think the v6 t5 wont bolt up to a v8, but i could be dead wrong on that one. but if it doesnt youd need to get a v8 t5 which shouldnt be that hard to find

i think you can get a GM goodwrench longblock 260 hp for around $1500, that wouldnt be too bad of an idea

iansmusical

Hey,

I'm also considering the V8 swap too just that I'm starting from a 3.1 and auto trans. How are you sourcing your engine as here in the UK they're hard to find and/or expensive?

I can't help but think someone on here said you'd need to change the bell housing with the V6 being a 60 and the V8 a 90 but also the V6 T5 isn't the same as the V8 T5... you'd probably break it as the shaft is a smaller diameter :-( Someone please correct if this is wrong!!!

Ian

metaylor

I was wondering if someone could confirn this because I was thinking of dropping a 350 into my 89 rs and the tranny would either be a t5 from a v6 or a t5 off of a 305. Does it matter what the year of the v8 is compared to the year of the tranny, because the 350's out of a 74 pickup and the t5's from an 86.

five7kid

iTrader: (14)

The year of the engine and transmission doesn't matter.

The type of transmission does matter. First, you'll need a V8 bellhousing. Then, the input shaft of the V6 T5 is smaller than the V8 T5, so you need a different clutch disk - word is there is a 4.3l V6 S10 disk that works. Finally, the V6 T5 is very weak - the V8 T5 is weak enough, but reduce the input shaft size even more, and you'd better not give it full power ever.

Project: 85 2.8 bird

some T5 info for y'all

http://www.flatheadv8.org/ernie/ernie-t5.htm

Popeye75

I have an 85 firebird with no motor that i am currently doing this conversion on. My car had a dead 2.8 v-6 motor, a chopped-up wiring harness and also has the t-5 manual transmission. I already have a 350 chevy motor ready to go and i am going to re-use the transmission that was in the car. I'm heading over to the local u-pull-it yard tomorrow and going to grab a v-8 bellhousing out of one of the camaro's there, but i'm hoping for a little more clarification on the clutch i need. i understand i need the clutch disk from a 4.3 v-6 s10, but is there a year range or does it matter? which flywheel should i use(i still have the v-6 one, a v-8 one or the s10 one)?

five7kid

iTrader: (14)

Dumb question: If you're going to get a V8 bellhousing from the JY, why not just get the V8 transmission as well?

I'm not sure about the year of the S10 clutch disk - the 4.3l application, though.

You need a flywheel appropriate for whatever 350 type you have. If 2-piece rear main seal, an '83-'85 thirdgen f-body V8 flywheel. If 1-piece rear main seal, an '86-'92 thirdgen f-body V8 flywheel.

MikeatACC

I'm about to do almost this exact same swap! The only difference is mine is a 1985 firebird and I have the automatic trans.

I would like to see if this is correct. I have been told that the automatic transmission will bolt up to a small block 350, and that I also shouldn't have to get new front suspension because the car, having the available 305 in some, used the same suspension on both models. I hope both of those are correct.

So from what I'm hearing I should, since I'm going carb'd 350, be able to pull everything out of there and drop the 350 in?

A few things I'm not sure on though...

1. wiring harness - will I need one for a 350 or will the stock one work?

2. Rear end - if I'm going stock 350 and as the poster said I'm not planning on doing anything other than headers and catback, will this rear end suffice? or will I blow the sob right out of it?

five7kid

iTrader: (14)

That is not correct.

Have you read the V6 to V8 swap sticky in the top section of this forum?

(And, it is not really the same topic)

MikeatACC

Kind of is the same topic actually and yes I have read it but I also know people who argue with a bit of the information in there.. I take your word over theres but that is why I was asking to confirm my questions

So I would need a whole new tranny? Which would also mean I would need new front suspension and rear end correct?

See the last time I read that thread was in 2007... some information has changed and if I wouldn't have been so impatient and just read it again I would've found the answers laid out in front of me..

Project: 85 2.8 bird

new tranny, new front springs.

why a new rear? enjoy your 3.42 gears.

ok, looks like you went back & read the sticky

metaylor

Double post, sorry

metaylor

I know with our local jnkyard, if I asked for a bellhousing they could get me one for almost any engine I wanted but as soon as I say "transmission" or "Engine" they ask me for a car make and year and if i'm not looking for a MANUFACTURERS SUGGETED REPLACEMENT PART, they won't sell it to me. it dimb, but hey, it's life. oh, and a lot of the trannys i see at the yard are pretty far gone.

89-bird

For anyone swapping a v8 inplace of the v6 . You can run your stock front springs , you will need a v8 or 4.3v6 bellhousing with a slave cylinder , and if you want to run your v6 tranny you will need to change the input shaft to a v8 26 spline which you can do if you know how and your local trans shop can get you a new shaft for under $200 which is better than paying for a junk yard v8 trans that may be junk for here in TN they sell for over $300. Good luck on your swap.

Atilla the Fun

Many of the '80s GM stick shift setups that weren't the V8 26 spline setup were the 14-spline input, very common with the 2.5L I4 and 2.8L V6, among others. This used a 9.2" clutch disc rather than the 305 Camaro's 10.4". Now, the V6 Camaro's T5 is just as strong as the T5 Ford used in the 2.3L Mustangs, and those T5s will live behind a stock Ford 5.0. This means that if you want to try it, you can put your 2.8 or 3.1 V6' T5 behind a 305 if you use the V8 T5 bellhousing. Now, the clutch and flywheel issue. Again, there is an easy solution. Centerforce makes a pair of flywheels, designed by Archie who does the V8 Fieros, and these accept the smaller 9.2" clutch. One flywheel is for '55-'85 SBCs, the other is for '86 and newer, including the LT1. You can then use any 9.2" clutch, including the one you might already have, you dont hafta use centerforce's matching one. Again, these T5s are NOT as strong as the V8 T5s, especially in first gear, and the input shaft. Forget abuse like powershifting, and they'll get you around for quite a while. G-Force Transmissions, Astro Performance and D&D Performance can all build you a killer T5, and I suspect they could start with a V6 case as easily as with a V8 one. Around here, V8 T5s just do not turn up at Pick-N-Pull. Not ever. Not the Camaro ones, not the mustang ones. That's why I found a way to use the V6 ones. The '88 and up V6 T5s are the improved "World Class" versions, but they have a 4:1 first gear, like the 2.3L Mustangs, so they work best with a 2.73:1 axle. My '85 2.8 T5 had a better 3.50:1 first, and despite not being WC, this is the one to use behind a 305. It has a 0.78:1 fifth gear.

Popeye75

I've been looking around locally for either a v-8 5 speed trans or the 4.3 bellhousing and haven't been able to turn up anything for weeks. i'd love to use the v-8 5 speed if i could find one, but they just aren't around. the only thing i have been able to find is the bellhousing out of a 4.3 s10 4x4. does anyone know if this will work? it should have the 10" clutch in it as well, correct? any help would be greatly appreciated guys!

snowman383

if you are wanting a 305 i will swap you 2 of them for the v6 and tranny one is rebuilt and the other needs to be rebuilt and comes with a 700r4 for a v8 and both have roller cams

snowman383

the tranny on a 2.8 v6 is called a 60* and the v8 is a 90* they are not interchangeable unless they have a removable bell housing and input shafts are also diff

Atilla the Fun

If you can get the trans from a 2WD S-10 4.3, that will survive a 305, but I have no idea about fitting it to your car. As for just the bellhousing? Won't bolt to a T5. 4.3 s-10s used the NewVenture 3550 instead.

HankL69

iTrader: (1)

I'm pretty sure the S-10 tranny will have the shifter located too far forward. I looked for quite a while for a five-speed for my F-bird. Finally found one on E-bay listed as coming out of an 84 Trans Am. The tag number said 84 F body so I bid and got it. Well I guess this was out of the rare V6 Trans-Am because it is the 14 spline box with 3.50 low gear! However the tranny had been gone thru and looked really good so I installed it . The shop that shortened my drive-shaft was able to order a 10.5 clutch disc for me. The 3.50 low gear works great with the 2.56 rear gear. I don't race the car so it has been holding up well so far. If I stumble across a WC t-5 I will probably jump on it but for now I'm happy. Last year on the way to the POCI meet in spearfish SD I managed to get 23 mph driving 75-80.

bentup78

I am swapping a 2.5 tbi and stock tranny out of my 84 Firebird for a carbureted 350 and 350 tranny. Will the stock drive shaft and rear end work? Also do i need a conversion kit for the mounts or can i use the mounts from the 350?

metaylor

You should be fine with the rear end and the engine mounts, I don't know about the driveshaft though...

bentup78

Im swapping a from v6 to 350 v8 and 350 tranny. Does anyone know if the drive shaft from the v6 will work and if not what drive shaft do i need?

metaylor

well, I mean, it's usually not so much as finding the correct donor car and just grabbing the drive shaft, What you need to do is measure the length (from the center of one U-joint to the center of the other usually) and from there you can measure the ones that you have and if they match up then you're good to go. you also need to know the number of splines on your input and/or output shafts if those aren't original. Like I said before though, I'm not a hundred percent, it's been a couple years since I did this.

five7kid

iTrader: (14)

Only if you have a 9" tailshaft TH350.

A driveshaft from an '82-'83 with 4-speed manual or 3-speed auto is the correct length for a 6" tailshaft TH350. Good luck finding one.