I read something about a 4.3 engine...i think. Is this a real substitute for the 3.1? If so how hard is the swap? and is it just that, an engine swap, with all the other components staying and working with the new engine?

 

its the 3.4, not the 4.3. do a search for the "3.4 swap boogie" by KED85

 

There's a 4.3 option that's been mentioned a lot lately by Dave. Definitely a cool swap that I considered, but its a 90* motor which means it will add weight to the front of the car and requires a different transmission (actually a bonus for me as I have a V8 trans I can use). Makes a LOT more low end power than a 3.4. The 4.3 pulled Jimmys/Blazers into the 15s and those are almost 4000lb trucks.

I think I want to do a 3.4 turbo swap in an '86 IROC.

 

i know, if hes looking for a "suitable" swap for the 3.1, hes looking for the 3.4. but yes, the 4.3 swap has been mentioned lately. its about as much work as swapping a 350, since its essentially the same engine w/ 2 less cylinders. if youre going for ease, 3.4 is the way to go. im not trying to persuade either way though, lol.

 

I have to agree with DrDave88 with that 1. I pulled my 2.8 yesterday, swapped the intake & plenum, motor mounts, tranny and clutch since it was new. Now I'm ready to put it back in. Not even a days work doing the 3.4 swap. Now there are some extra steps you can follow ( Keds85 boogie), but as far as ease the 3.4 in quick and simple.

 

FWIW, the late model 3800s and cadillac pre Northstar 4500/4900 V8 share the same bellhousing pattern as the 2.8.

 

That may be true, but then you have to fab up the electrical harness and the engine mounts yourself. They're not a direct bolt in swap.