i have a 4.3L out of a 91 blazer in my 93 blazer. i have not looked into it much, i had glnced in the engine bay - but if im not mistaken is it carberated? and if so how hard would it be to attach the 4 barrel holley i have laying around?

 

Your '91 should be TBI (throttle body injection). If you remove the air cleaner, you should see 2 pods hanging above the throttle body.

They do make 4-barrel manifolds for the 4.3L v6, but you would want to make sure you aren't over carb'ing the engine. I don't think you'd want much over a 550cfm 4-barrel for the 4.3L unless you were to put in a high rev'ing cam, install headers, and full exhaust.

 

well, i dint wanna go that far. i just was thinking i could get a few extra hourse with the piece i had laying around. thanks for saving me from making a mistake.

 

you can put an adapter on it to put the carb on... but chances are your mileage would suffer and you wouldnt gain much for hp. i wouldnt mess with it if your tbi is functioning correctly.