Mad Hatter

Hi, so i own a 1988 Pontiac Firebird as my daily driver, and it has the tiny, unreliable, bad mileage 2.8L V6, and i want to drop a 4.3L V6 into it for a bit better power, mileage and reliability, problem is, i dont have a ton of money, and i need to make sure i know everything will work properly, because i cant mess around with getting it running after what was supposed to be a quick swap. i simply need to know, will i be able to put a different bellhousing on the current borg warner T5 manual to do this swap, or do i have to get a whole new transmission? been trying to figure this out for weeks, my friend tells me itll directly bolt up, but its a 60 degree V6, and the 4.3L are 90 like the V8's, so it doesnt make sense to me....any help will be greatly appreciated, thank you

Eric-86sc

iTrader: (18)

You'll need to use a v8 t5 bell housing since the 4.3 uses a sbc bolt pattern. The original trans can be used with the correct clutch, I'm not sure off hand what that would be but searching v6 trans behind a v8 will give you the part numbers.

Besides that, why use a 4.3? There is a reason you don't see a ton of 4.3 swap threads on here, its basically all the cost an work of a v8 swap for less power and power potential. Based on your criteria of an easy and cheap swap, why not swap in a 3.1 or 3.4 in place of the 2.8? Besides an injector change all you pretty much haver to do is take the 2.8 out and put the other motor in. You could also reuse your original bell housing and clutch no problem which is a $100 savings minimum right there.

Mad Hatter

Well at this point i'm beyond tempted to just maintain the 2.8 and build up a V8 like i want to long term. the idea was to keep it lighter weight, better balance, and more daily driver with a little kick hoping i could get a 4.3, performance cam, and have a nice little boost without having to go extreme, also, i refuse to go automatic. i cant stand auto. this is why i ask these questions. i specialize in V8's, and it looks like i should just stick with them. i was intending to use a 4.3 to just get a nice 180-195 horse range, keep the fuel efficiency up, and just not have to think to terrible much about needing anything but regular maintenance. at this point ill likely just maintain the V6, finish my 82 Camaro project, and when thats on the road build up a 400 small block and just save for a T5 magnum trans

Eric-86sc

iTrader: (18)

That would be a better plan. There are some things you could do to the 2.8 to help it out a little bit such as ported heads, intake and a delta 260 cam or even an ebay turbo build. The best part about that is v6 parts are so cheap they're almost free so you can have extra heads/intake to port and swap them on the car when your ready. A 4.3 would pretty much be money down the drain since performance parts for them can be expensive and their pretty much a sbc with 2 less cylinders so no even light weight.

Mad Hatter

yeah, ill probably just build up a V8 for it. i was kinda hoping to be able to do a V6 without going broke and having it be overly difficult, but it does seem rather pointless...thanks for the help! i appreciate it!

Night rider327

iTrader: (13)

The 2.8L and 3.1L weigh around 350 lbs
The 4.3L weighs 425 lbs
The iron head/intake V8 weighs 575.

535 lbs with alum intake
500 lbs with alum intake and alum heads
490 lbs with above plus alum water pump
480 lbs with above plus mini starter

Weight gain is not that much really.

danryanm

I agree, the cost of doing such a swap can potentially snowball to be more than converting to a V8, with less gain. That being said, I am a big fan of oddball stuff, and it is definitely doable with common parts. The V8 bell housing (for the F-bodies only) will bolt up to the transmission. As you've read above, you may have to trim the input shaft length if you have too much runout (but I didn't have to.)

What I can't tell you is which clutch kit and flywheel combo will fit in said bell housing. A 168-tooth may not fit, but a 153-tooth is guaranteed (just make sure which one your block can accommodate). All that's left is to find a clutch kit. The Astro van kit works for the 168-tooth. Someone else will know better about the 153-tooth.

midias

They made a 2 door T5 Jimmy, blazer with a 4.3 If you can find one I bet you can swap tail housings and make it fun.

Mad Hatter

well in the end here my 82 Camaro project went sour thanks to the heavily rusted undercarriage and im getting a 4.3 for a trade on the engine i had in it. 19,000 miles on the 4.3, and its a vortec with a 195 horse rating and 255 torque. exactly the power i wanted if i did a V6, and with the aerodynamics and the weight difference between my firebird and the truck it came out of, should get at least 27 mpg city. so im happy. just need to get a posi soon..

novaderrik

a mild 350 will make a lot more power than a 4.3 and probably get better gas mileage, too... and the 4.3 isn't really that much lighter than the 350 it's based on: maybe 50 pounds, tops.. swap some aluminum heads and headers onto the 350 and it weighs as much as a fully dressed 4.3.