the 4.3 is a 350 missing 2 cylinders and the TB isnt the same the 4.3 is TBI the obdII would be easier to tune as no one tunes the 3.4 at least i couldnt find anyplace within 100 miles form me

 

the location of the throttle body on the central port injection (cpi) 4.3's is fairly close to that of the 3.4, its just turned towards the driver side a bit. it all depends on you though. do you want to build an engine to fit the supercharger, or build a car with a fast engine?

 

Well this supercharger like the 671 need's the fuel to be put in on top of the supercharger. I've been told the supercharger will run hot if you don't. Since I have this supercharger I'm going to use it, I think it will make very good power on the right engine. I'm thinking the 4.3 might be a little big for it. If using it on the 3.4 is not a good idea either I might put on a Buick v6 with a Holley 4 barrel in a old Monza I got. It would be a lot easier not trying to have it fuel injected. Thanks for your help! Tim