V6 TBI to V8 swap

[nlauffer]

This isn't exactly a 73-87 Chevy truck question but sort of. It involves the engine I am building for my 83 SWB automatic.

My 92 v6 5 speed just dumped oil out everywhere and potentially toasted the motor. It's dark and my wife was driving. I haven't seen it yet.

My question is can I use my v8 and put it in place of my v6 using a v8 TBI intake?  Will I have to change throttle bodies or change ECM and can I make my 83 HEI distributor work?

This is not my ideal situation and don't want to but I need a vehicle. My 83 is not ready to drop the motor in.

[Irish_Alley]

i wana say no. ideally the 4.3 and a v8 would still only use two injectors but there is more to those blocks than 2 cylinders missing. now if you grab the wiring/ecm off the v8 tbi intake then that should work. but since your 93 is a stick i wana say you can get away with just putting a carb motor in her since your transmission is not electronic. now will you throw some codes, yes. but it shouldn't matter since you control the gas and you control the shifting

[Stewart G Griffin]

The throttle bodies are exactly the same between the 6 and 8----but the injectors sizes are different.  The ECM may need to be reprogrammed or replaced----mainly because of it reads off the 6 cyl ignition pulse right now vs. 8 cyl.

Why not call these folks.  i'm sure they can set you up right:
http://howellefi.com/

i'm thinking the easiest way would be to get a reman 4.3 because if you go 8 then the exhaust may have to be changed? (not sure on this)

[Captkaos]

If you need this running in a pinch, the existing injectors "will" work, but not optimally.  You will have to get a V8 chip for your ECM though and a distributor for a TBI with all 8 posts...  Your HEI won't work without causing issues.

[nlauffer]

I forgot to update. She was wrong. Not oil. It was the lower radiator hose. Thermostat stuck and built pressure. Fixed and fine now. Good thing is it made me get back on my project.