needing exhaust advice please!!!!

85montecarloinNY

n00b
Thread starter
Jun 6, 2020
1
1
I am starting to build my 85 Monte Carlo. It still has the original 4.3L in it....I know boat anchor! Here's my issue...I won't be able to do the motor and trans swap right away but i need to put in a whole exhaust from manifolds to tailpipe. Everywhere I look there is nothing for an entire exhaust system. Any clues out there? Thanks in advance!
 

pagrunt

Geezer
Sep 14, 2014
6,802
113
Elderton, Pa
First, true duals or stock type dual tail pipes like a SS or 442? True duals will require you to have a set of down pipes for the V6 manifolds then a set of pipes to connect the V8 manifolds or headers to the system. Sometimes it's easier to wait until the swap to do the desired exhast set up. But regardless spend the extra coin on stainless.
 
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ck80

Comic Book Super Hero
Feb 18, 2014
2,811
113
I doubt you'll find a complete manifolds back kit for the 4.3l. Actually doubtful back in the day too.

My recommendation to you? Pick an acceptable exhaust setup for what your engine plans are in the future. If your car has overdrive, and you're comfortable building a 200-4r for it, go ahead and buy a dual exhaust crossmember for it. Then it's just a case of fabbing up something that connects to that for now, and getting use out of it after your swap. Wouldn't be too hard, a 4.3 is just a 350 with 2 cylinders lopped off design wise.

Of you search the forum, some members here have had issues with tailpipe bends on some cat-back kits out there. So do research on that.

I'd try to find a good local exhaust shop that will mandrel bend you some stainless pipes and install mufflers you bring them. That's the best fit for the body/undercarriage.

Or, if you just want cheap and disposable, buy it piece by piece from a parts chain and do stock replacement with used manifolds off something someone is parting out.
 
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565bbchevy

Geezer
Aug 8, 2011
8,448
113
Michigan
On my Regal when it still had the 307 I installed a stock dual exhaust 2.25" cat back system for a 442 and then later when I installed the SBC and headers I used the exhaust where it splits and added an X-pipe to the factory duals so I could adapt it to the headers.
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Oct 14, 2008
7,471
113
Melville,Saskatchewan
I did the same thing with a Hooker cat back, custom down pipes and a compact X pipe to tie them together.
 
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Doug Chahoy

Comic Book Super Hero
Nov 21, 2016
2,549
113
Ther are so many variables here, what trans do you intend to swap in, how much can you do yourself? Are you going to run cat converters ? Are you like most of us, with no intention of resale? I’d get the crossmember and true dual stainless system first. I’ve always preferred MagnaFlow, but went with Pypes for my Elco. Find an exhaust shop to make up your temporary down pipes .
 
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