I have a 4.3v6 in 89 caprice that needs to be replaced. I also have a 350 from a 91 chevy truck sitting in my garage. How much trouble would it be to put the 350 in the car and is it worth the trouble or should i just rebuild the v6. Also if i put the 350 in what parts would i need to purchase. Any help will be appreciated.

As long as you stick with the L05 variant of the 350, it shouldn't be too hard, though you will need to replace the trans as well if you want the trans to last a week behind that 350. Use the entire 350 setup including the throttle body. You can use the accessories off of the 4.3 - they should bolt right up. You will also need to replace the MEMCAL in the ECM with one for a V8 - the 305 MEMCAL will actually give you a little performance kick over the 350 part as the 305 has a more aggressive distributor advance table. Once you get it all up and running, you might want to consider running a good quality diesel motor oil, CI4 rated, such as Shell Rotella-T as your '91 truck engine will have a flat tappet cam.

Thanks for the info. I have one other question. How can i tell which trans came with the car without removing it. I know the car is still in original condition and no parts have ever been replaced. It's a one owner with 110,000 miles.

most likely the th700-r4 which is a 4 speed with overdrive.
if you dont have overdrive, then its the th350

either way, both transmissions should work behind a 350 if you do some modifications to the clutches.

1989 w/ V6 should be a TH2004R if it's 4-speed (overdrive). If it's 3 speed it will be a TH200C. The TH350 was not available in 1989 in this car. Pan shapes -

http://silicon212.org/pan_id.jpg

1. Aluminum powerglide (for reference only)
2. TH200/TH200C
3. TH350/TH350C/TH375B/early TH250 (later TH250C has "X" shaped crossrib, same pan shape)
4. TH400/3L80/TH375
5. TH2004R
6. TH700R4/4L60/4L60E
7. TH4L80E (400 overdrive)

oops
:lol:

wait, i thought he was talking about the trans behind the 350
i got confused.

I've been looking around and i have found a few v8 caprice donor cars but none are fuel injected. My question is does the donor need to be the 89/90 caprice with fuel injection, or can it be any chevy v8.

I've been looking around and i have found a few v8 caprice donor cars but none are fuel injected. My question is does the donor need to be the 89/90 caprice with fuel injection, or can it be any chevy v8.

Your car is set up for FI, so that's what I'd stick with. It's better, anyways.