85 tbi 4.3l to a tbi 305 or 350

[85monte88]

looking to swap my 85 4.3 out to a tbi v8 preferably a 350, as far as computers what other things would i might need also my trans is 2004r which is the 4 spd would that bolt up what about exhaust i know ill need v8 headers.. any info would help thanks.

 

[beenen]

I'm in the process of doing this..all I think you need would be of course the exhaust manifolds / headers, complete TBI system for a 350 V8 and the computer with it (I read up on using to see if you can still use the V6 computer and so far I think the answer is no), motor mounts for a V8, not sure if you would need a newer pump..you already got the FI tank and fuel lines..

someone else will chime in that knows more about this than me..as I am looking for more info myself

 

[MadMax]

i have done this several times. use same wiring harness as the original v6 and just switch the brain out to a 305/350 tbi truck brain. works every time.

 

[Dave V]

what you want to do is an easy swap just need the 350 chip from where ever you get the motor or you can run an aftermarket chip like i am. i have a jet chip in my motor and i love it. i did a tbi swap from a carb 305 and i hands down love having something that is so reliable and if you can keep your foot out of it fuel efficent; the 200r4 is a perfect trans for your setup.

 

[dogsht]

When you take the 4.3 out you might consider just pulling the trans at the same time. Then either install it yourself or take it to a shop and have them install a good shift kit such as one from ckperformance.com. An inexpensive trans cooler wouldn't be a bad idea either and would be easy to do at that time. Oh yea my vote would be to get an inexpensive custom chip at least if you are going to do headers a 160 degree thermostat and especially if you are upgrading the cam.

 

[Dave V]

custom chips are the way to go if your gonna do some mods i was able a few years back to help chevy hi performance for a tech article and got a jet stage 2 chip for free and overall im happy with it.

 

[beenen]

what you want to do is an easy swap just need the 350 chip from where ever you get the motor or you can run an aftermarket chip like i am. i have a jet chip in my motor and i love it. i did a tbi swap from a carb 305 and i hands down love having something that is so reliable and if you can keep your foot out of it fuel efficent; the 200r4 is a perfect trans for your setup.

Do you know about what your seeing in terms of MPG wise?

thanks

 

[outlaw1985]

wow i thought i was the only one out there with this idea im new and young to the swap world anybody got some more pointers.Also where do u think i can get one of those jet chips?

 

[85monte88]

preciate the replies i stumbled upon a 350 engine/trans and what ever i need out of a 90 suburban which runs for a to good to be true price but hey the 4.3 has to go i will tear the 350 down ...so what ive read up on my swap should be somewhat simple if i get everything engine trans i know people say just the swap chips im going to grab the whole cpu, the manifolds to the cat anything..now other than that what about the drive shaft and rear end any suggestions

any other info would help and will keep yall updated