How to swap a V6 TBI with a V8 TBI in an 87 Mote LS?

[Chevelle_68]

Hi everyone.
I just bought myself a 1987 Chevy Monte Carlo LS with some work on it.
The car has a V6 TBI engine and a TH200 Trans in it. The engine has seen its best days, so I am going to swap it out with a 350 TBI from a 1990 Chevy G20 Van. In the same process I am putting in a recently overhauled TH700 Trans.
So to my questions:
What needs to be changed on the car to make the V8 fit instead of the V6?
Can I reuse the wiring from the V6 TBI system or do I need a new wiring harness?
Should I swap cam in the engine since it has been in a Van and are now going into a much lighter car?

Thanks!!

HD 8)

 

[84sscutty]

It;s a simple swap. Change your frame pads(mounts), shroud, and upgrade the fuel pump to like a tbi camaro or tbi truck pump. The wiring will be the same. Then call Brian at www.tbichips.com He can burn you a chip for a stock v8 conversion for $150 or less. Make sure you have the right transmission crossmember and make sure you get that 700r4 adjusted right or you will burn it up in no time flat. Other than that I believe thats about it.

 

[Chevelle_68]

Thanks for the reply.
The first plan was to put the engine in a 1977 Opel Commodore GS, but sold that car before I got anything done. So for that swap I bought a wiring harness from Painless Wiring for a TBI engine. So I guess I don’t need that harness any more.
How do I hook up the wiring for the TH700 lock-up? I have a B&M lock-up controller kit I bought for the Commodore. Should I use this one?
When it comes to trans crossmeber, I guess I just have to modify the one that is already there or make a new one. There`s not too many Monte Carlos around in Norway, to take parts from.
Where can I buy new frame pads?
I guess I might go for electrical fans for the same reason as the crossmeber. It’s hard to find used parts for these cars in Norway.
Do I need the change the front springs?

HD 8)

 

[joevk78]

I don't mean to step on anyone's toes here, but you'll probably need a bit more than a V8 chip and a fuel pump. I had a GMC Sonoma with the TBI 4.3L, and my current C1500 has the TBI 350. I did lots of research on TBI V8 swaps when I owned the Sonoma, and I've been researching how to make reliable power with the TBI system my C1500 has. I'm no TBI wizard, but I've learned a few things. The first place that comes to mind for info on the swap is this: http://www.tbichips.com/faq.htm There's also lots of information on Chevy truck forums, and 3rd-gen Camaro/Firebird forums, but out of respect for this site, I won't give links to those sites, unless it's allowed (I'm new here).

 

[Chevelle_68]

Way do I need to change the Chip? I`m planning to use the same control boxes that was used when the engine was in the donor wan. It will have the same trans behind it as well. The only thing that will be different in the drive train is the rear end gears.
Or is the reason to swap chip that I`m putting the engine in a smaller and lighter car?
So if I understand correctly, the TBI wiring will be a direct fit, but will it work with the TH700 trans?
Should I use the TBI wiring from the van that already had the TH700?
Or will it be best to put in the new wiring from Painless that is made up for a TBI engine and an TH700 trans?
Can I use the fuel pump from the van?

Sorry for the shitty English bay the way 😳


HD

 

[Chevelle_68]

????

 

[RITTER]

You will be just fine using the computer from the van. If you put a performance camshaft in it you will want a performance chip made for it though. It will run without one but it will run better wih one

You do NOT need a different fuel pump. A 4.3L TBI, 305TBI and 350 TBI all run a the same fuel pressure.

You do NOT have to change the frame mounts. The 4.3L uses the same frame mounts as SBC.

The wiring harness should all be a plug and play as well.

 

[jrm81bu]

You do NOT have to change the frame mounts. The 4.3L uses the same frame mounts as SBC.

You WILL need new motor mounts. The 4.3 does NOT use the same mounts as a sbc.

Ritter, check the numbers when you are at work. A small block takes Ballkamp number 6021179 for both sides, the 4.3 uses 6021373 for the right and 6021379 for the left.

 

[RITTER]

I stand corrected 😳 The mounts are indeed different

 

[beenen]

I know this is a somewhat old thread but I'm swapping out a 4.3 TBI to a 305 TBI..for the wiring harness can I use one from like a 305 TBI camaro ot T/A? sorry kinda new at this TBI stuff

could I use a 1995 305 tbi harness on an 1988 305?