Need engine swap advice -1986 Monte Carlo Ls

[Anthony Nyz]

New to the forum, so please bear with me.

Bought a 1986 monte carlo Ls with the 4.3 V6/auto 3 speed trans this past tuesday. This past wednesday, the engine seizes. So now I'm forced to do an engine swap. I've decided to go in the small block chevy direction, specifically a rebuilt 350 from jegs.

http://www.jegs.com/i/Chevrolet-Performance/809/10067353K8/10002/-1

I have a few main questions, but any and all advice is appreciated since this is my first time working on a g body.

Will I have to worry about different/custom engine mounts with this engine?

Will I need an adapter plate/different bell housing to mate my existing trans with this new engine?

Can anyone recommend a harness? Not sure what I'd need as far as engine management. I'm assuming it would be rather simple because the engine is carbureted.

Should I upgrade to a bigger radiator going from a v6 to a v8 in this application?

Any information would be great, thank you.

 

[pmoore4321]

Will I have to worry about different/custom engine mounts with this engine?
(2) OER 332648
(2) Anchor 2292

Will I need an adapter plate/different bell housing to mate my existing trans with this new engine?
I was going to say "no", but can't remember what trans is in the V6 MC

Can anyone recommend a harness? Not sure what I'd need as far as engine management. I'm assuming it would be rather simple because the engine is carbureted.
Does your state have emissions testing? Air conditioning requirements? You don't really need the harness with the setup you will be using.

Should I upgrade to a bigger radiator going from a v6 to a v8 in this application?
Spectra CU162

Engine brackets? I would use a serpentine system from a 90s pickup.

I believe the V6 is injected, no? fuel pump setup?

Lots of other little details (PS pump, water pump, trans kickdown, etc)

If you have the details worked out and the parts ready to go, you could complete the swap easily in a weekend.

 

[pmoore4321]

I've had more time to think about your plan. What are you trying to accomplish? You're going to spend a bunch of money for very little gain in my opinion. You will have the "Midas Touch" by the time you're done for sure. Midas well do this, Midas well do that....

 

[Anthony Nyz]

Honestly, I'm just trying to go for reliable daily driver. I've had enough with the constant break downs/waiting for tow trucks. Having the engine go the day after I bought it definitely put me behind the 8 ball. I have 2500 in it now, and I'd like to keep the whole project under 7000 or 8000 all said and done. Do you have any suggestions about a possible different direction I could go engine wise for less money? I drive about 75 miles a day for work and while I understand she's gonna be horrible on gas when she's done, I really just need something I don't have to worry about in my driveway.

 

[Anthony Nyz]

Also, the transmission is a 3 speed th-200c I believe. I live in PA, so my state does require emissions testing, and while ac is not necessary by law, I'd like to have it. The original v6 was efi from the factory, so I'm guessing at the very least I'd need a different fuel pump. Thank you for your help so far.

 

[L67ss]

You can use the accessories from the 4.3

 

[Opie Knievel]

I'm preparing for a 350 swap for my '86 Monte Carlo with a 4.3. I'm going with a used Vortec engine. The 350 will bolt straight to the 200 transmission but the 200 is junk in most people's opinion. I'm rebuild a TH350 for mine right now. If you drive a lot of miles everyday, an overdrive transmission would be the way to go.

I'm pretty sure the V8 radiator is a little bigger. You'll need a V8 fan shroud for sure. I lucked out and found a V8 Monte Carlo that I bought dirt cheap for parts.

You can buy a fuel pressure regulator to keep the fuel pressure low enough for a carb or remove the electric fuel pump and either get a sending unit from a V8 car or modify the sending unit you have. You'll need to make sure you get an engine that has the fuel pump mounting location drilled if you remove the electric pump.

I'm pretty sure the motor mounts are the same on the 4.3 and 350 but I can't remember for sure.

 

[Opie Knievel]

You can use the accessories from the 4.3

I forgot to mention that. All of the accessories will bolt to a 350. I was originally thinking about transplanting a serpentine belt setup but after thinking about it, it would cost a lot more and would require new A/C lines, plus the accessories to fit the serpentine setup. Using the 4.3 accessories is the cheapest, easiest way and you can keep A/C without having to get custom lines made.

You could keep the fuel injection and get a TBI intake for the 350. I'm sure you would need a better tune in the ECM for that but it's an option.

 

[pontiacgp]

I agree that transmission will not last behind a 350. Why not look for a good used 350 with a 200 r4 package.

 

[Andebe]

I've had more time to think about your plan. What are you trying to accomplish? You're going to spend a bunch of money for very little gain in my opinion. You will have the "Midas Touch" by the time you're done for sure. Midas well do this, Midas well do that....

Very little gain? Going from a dead motor,to a new one,seems pretty significant to me. But hey,Im new here...