Trevor Tarry

First off hello third gen! I picked up an '88 firebird with a 2.8l, t5. The car is completely rust free and worthy of more than a 2.8l. I have a complete running 4.3l 5spd in a 91 s15 4x4 with a rotted body/cab.

I have searched and can only find threads talking about this swap but not much actual details.....

My questions are: What bellhousing to look for, year/model/option? What motor mounts or modifications, year/model/option? Will i be able to get 4.3l pcm to talk to the gauge cluster, tips?

novaderrik

the 4.3 is a 350 missing a middle cylinder on each side... the trans you need would be from an F body V8, as would the bellhousing. the flywheel from an 86 and later 305 or 350 will work, but you might be able to use the larger truck flywheel and clutch that's on the engine already if you can physically bolt the F body bellhousing over it, which i don't think you can.

the motor mounts from a V8 zF body will fit, but they will need to be located back farther on the frame: i'd bolt the engine and frame mounts to the engine, then set the engine and trans in the car with the torque arm, driveshaft, and trans mount bolted in place to see where the mounts wind up on the frame. then just weld them down or drill holes and bolt them in place. the back of the mounts might wind up hanging off the back of the crossmember, so you might need to weld metal to it to build a platform to bolt/weld the mount down to...

then it's just a matter of hooking up fuel and coolant lines as well as electrical and exhaust systems.. and when you are done, you will have a car that is slower than a 305 that is easier to swap in and probably uses more gas, too.. but it should at least be faster than the stock 2.8, so that's something, i guess..

Trevor Tarry

Well thanks....i guess.

I have found a few more real details.

84-92 f-body Camaro/firebird V8 T-5 bellhousing. GM# 14075723

85 Astrovan 4.3l flywheel. GM# 388001

85 Astrovan 4.3l clutch kit. disk, pressure plate, throwout. GM# 381179


Now I still need to figure out the throttlebody pcm to cluster/wiring harness. Any input? Concerns? Comments? Tips?

novaderrik

if that Astro flywheel is the large 14" one that they used in trucks, then it probably won't fit inside the bellhousing.. you need an 86 and later 12.75" flywheel and 10.5" clutch setup, the parts for an F body will work on a 4.3.