My tailpipe is the size of a cocktail straw

[BVRPLZR]

Ok not exactly, but it's definitely smaller than stock.

I'm the third owner of an 88 Chevy G20 van with a basically stock 350 (iron manifolds, factory y-pipe, cat, etc)
At some point the previous owner had the exhaust from the cat back replaced by someone who cobbled together such a goofed up hack job that I'm honestly honored to be able to own such a magnificent piece of engineering. A real monument to apathy.

I can't remember the exact measurement but basically, the exhaust system is being lightly choked out by a 1.75" replacement pipe and bargain bin muffler. Pretty sure stock was at least 2.25" on these vans.

Plan #1:
- Keep the iron manifolds because they don't leak and to keep heat down
- Keep the factory y-pipe and match that diameter to a high flow cat and a reasonably quiet chambered muffler

Plan #2:
- Put headers on it
- Figure out the rest

I like plan #1 because it keeps everything nice and easy and stock. This is not a high horsepower engine, and I have no plans to make it that way. I just want it to breathe at least as well as from the factory and maybe a little better if I can.

Plan #2 is appealing because of the little voice in my head saying 'why not', but I'm hesitant mostly because of the heat issue. I don't want to start melting wires and cooking my feet. I've never had headers so I'm just basing that on assumptions and could potentially be convinced otherwise, but I'm not trying to get into expensive ceramic coatings and the like. I'm also hesitant to go this route because I'm not sure I want to have to figure out a dual exhaust set up (nor do I want to buy 2 cats and 2 mufflers)


It seems like most of the exhaust threads I've read dealt more with upgrading from stock, but I want to upgrade to stock....
I guess I'm just looking for opinions.

 

[0xDEADBEEF]

I vote #1.

Doing headers on a van doesn't sound very fun.

 

[Komet]

If it were my van, absolutely #1. But it's your van, so absolutely #2 and take pictures.

 

[Road Trip]

Ok not exactly, but it's definitely smaller than stock.

I'm the third owner of an 88 Chevy G20 van with a basically stock 350 (iron manifolds, factory y-pipe, cat, etc)
At some point the previous owner had the exhaust from the cat back replaced by someone who cobbled together such a goofed up hack job that I'm honestly honored to be able to own such a magnificent piece of engineering. A real monument to apathy.

I can't remember the exact measurement but basically, the exhaust system is being lightly choked out by a 1.75" replacement pipe and bargain bin muffler. Pretty sure stock was at least 2.25" on these vans.

Plan #1:
- Keep the iron manifolds because they don't leak and to keep heat down
- Keep the factory y-pipe and match that diameter to a high flow cat and a reasonably quiet chambered muffler

Plan #2:
- Put headers on it
- Figure out the rest

I like plan #1 because it keeps everything nice and easy and stock. This is not a high horsepower engine, and I have no plans to make it that way. I just want it to breathe at least as well as from the factory and maybe a little better if I can.

Plan #2 is appealing because of the little voice in my head saying 'why not', but I'm hesitant mostly because of the heat issue. I don't want to start melting wires and cooking my feet. I've never had headers so I'm just basing that on assumptions and could potentially be convinced otherwise, but I'm not trying to get into expensive ceramic coatings and the like. I'm also hesitant to go this route because I'm not sure I want to have to figure out a dual exhaust set up (nor do I want to buy 2 cats and 2 mufflers)


It seems like most of the exhaust threads I've read dealt more with upgrading from stock, but I want to upgrade to stock....
I guess I'm just looking for opinions.

There's a gentleman on this forum who's a subject matter expert on getting a van
to perform way better than it should. Here's hoping @L31MaxExpress sees this and
can share some of his firsthand experience on finding/removing performance bottlenecks
from the exhaust. (And everything else.)

 

[L31MaxExpress]

My 83 had OE catless 2.5" duals and factory tubular manifolds. My 87 had dual 2" outlet manifolds to a 2.5" Y-pipe, 2.5" single inlet/dual 2" outlet muffler and dual 2" pipes. My 92 had dual 2.25" outlet manifolds, 3" Y-pipe and single 3" all the way out.

Personally on the one I built to cruise, I am using option 3 on the 87. Holley Hooker 2.5" outlet manifolds. Inexpensive and flow better than the GM manifolds. The GM L31 spark plug heat shields fit them. Dual 2.5" cats, dual in/dual out magnaflow and dual 2.5" tailpipes behind the driver rear wheel.

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[RichLo]

All I could think of reading that OP was a 350 breathing through 1.75" single pipe must sound like a deer whistle, lol. You could upgrade to some electrical conduit if you really want to scare critters away!

 

[L31MaxExpress]

All I could think of reading that OP was a 350 breathing through 1.75" single pipe must sound like a deer whistle, lol. You could upgrade to some electrical conduit if you really want to scare critters away!

The pellet box cat is an even bigger cork. One could literally cut the pipe off at its outlet and it would still be quieter than 95% of the modern vehicles running around now. It is literally a shell, packed full of beads with stainless mesh holding them in place.

 

[L31MaxExpress]

Cheapest option would be keep whatever manifolds you have, keep the flange and 2" of pipe after the flange, weld 2.5" pipes over those that are bent to mate to a 2.5 to 3" merge Y, then a 3" high flow cat, single 3" pipe, 3" muffler of your choice and a 92-95 350 G20 3" tail pipe. Personally I would swap to headers or the Hooker manifolds. Summit actually sells a header/dual exhaust kit but they do not come with cats.

 

[Caman96]

What….no pictures of the cocktail straw?

 

[Caman96]

Can also be used as brake lines.

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