Exhaust

[Doug Long]

I am looking for a 3 inch bolt on exhaust for my 76 K20. The problem seems to be the 3 inch size. Does anyone have any suggestions on where to buy one?
Thanks,

 

[Grit dog]

Holley makes one.
But you didn’t specify single vs dual.
Although dual is assumed, but for 3” pipe and any mild 350, 3” duals are way overkill.
If you’re actually sizing the exhaust right and have a high performance engine, your best bet is get a 3” system fabbed by a muffler shop.

But if you have a <450-500hp engine and budget is a concern (IE a bolt up system) then get smaller exhaust.

 

[Doug Long]

Thanks for the response. Yes I am looking for duel exhaust. The truck has a 350 in it and the current exhaust is pretty rusted from the truck sitting for years. Sounds like I am better off going with the 2.5 inch exhaust that is sold pretty much everywhere.

 

[Grit dog]

Wow! That truck looks beautiful! Original paint? Rock guards look OE still. ..
Yes if it’s a stock 350 and you don’t have plans for big power, 2.5” will fit the bill 100%.

 

[Doug Long]

Yes original paint. It was an Oregon truck that I purchased from a guy that inherited it and did not drive it in Nevada. The rock guards are OE. We took the rims and powder coated them black and have been going through the engine. New radiator, rebuilt the carb, new plugs, wires, 32 inch tires, and some chassis paint. My son is driving it as a daily driver right now for the winter until the weather breaks. Super clean with very little rust on the bottom of the passenger side front fender. Bed has had a mat in it since original and no rust there either.

 

[75gmck25]

This is very similar to a question from earlier this week.

AFAIK, if you want something off-the-shelf and for a moderate price, there are multiple 2 1/4” exhaust systems available, probably only one 2 1/2” system, and nothing in 3” for a 4WD truck.

It may not be that hard to fabricate your own 2 1/2” exhaust from one of the universal kits, but 3” is very hard to fit around the transfer case cross-member. Fabrication by a professional shop could be in the $1k range or higher, depending on the quality of the pipes they use.

 

[PunH2O]

305. 2.5 all the way. Summit muffler

 

[80BrownK10]

Yes original paint. It was an Oregon truck that I purchased from a guy that inherited it and did not drive it in Nevada. The rock guards are OE. We took the rims and powder coated them black and have been going through the engine. New radiator, rebuilt the carb, new plugs, wires, 32 inch tires, and some chassis paint. My son is driving it as a daily driver right now for the winter until the weather breaks. Super clean with very little rust on the bottom of the passenger side front fender. Bed has had a mat in it since original and no rust there either.

If it's that clean, what state are you in? I wouldn't be dailying it in salt country. Good way to ruin that beautiful truck.

 

[midwest]

Just curious....When I bought my truck it had 3 inch exhaust on it with headers. I took the headers off and went with stock manifolds but kept the three inch. I had the motor rebuilt and a mild cam in it but it is basically the stock horsepower give or take. Is having the 3 inch hurting anything, or just not necessary?

 

[CalSgt]

With dual exhaust, 2 1/4" is more than enough for the average SBC

Just curious....When I bought my truck it had 3 inch exhaust on it with headers. I took the headers off and went with stock manifolds but kept the three inch. I had the motor rebuilt and a mild cam in it but it is basically the stock horsepower give or take. Is having the 3 inch hurting anything, or just not necessary?

Less exhaust gas velocity, reduced torque, possibly noisier

 

[RecklessWOT]

Just curious....When I bought my truck it had 3 inch exhaust on it with headers. I took the headers off and went with stock manifolds but kept the three inch. I had the motor rebuilt and a mild cam in it but it is basically the stock horsepower give or take. Is having the 3 inch hurting anything, or just not necessary?

Not gonna hurt anything at all, just no real benefit. I bet it sounds real cool, but that's about it. No performance gain with a mostly stock engine even if you have a mild cam. Dual 3" does not become necessary until you're making some serious power.

Now if it's a single, 3" is right where it belongs. My suburban is stock (minus the flowmaster and cat delete) 3" single all the way from the y pipe back.

 

[midwest]

Thanks
Basically the truck had the exhaust on it when I got it and it had some issues. I took it to a local shop I trust to have it replaced. When I got back to pick it up he had fixed a couple things, added some new hangers, and said there was no need to replace it. So it has been as is every since. They just go over the rear end and then angle down, so it's not like he put it on to show off, you cant really see unless you bend down and look. Once it's time to get it replaced Ill look into option then. I have no complaints with it as is but I was curious if I could be causing some problems.