Exaust Sizes

[ClassicRedneck05]

I have a Stock 350ci in my 72 Chevy LWB i have headers but im bout to buy new ones i was wondering if it would hurt or make a diff to go from 2 1/2 pipe to 3"exaust into my Bullet Mufflers?

[Boise69]

I posted a similar question and the answer i got was a 3" pipe will rob HP from a stock or mild 350 ci. And all i read convinced me to stay with 2.5

[ClassicRedneck05]

lol sounds good to me only thing im changing is the headers and then puting stainless pipe then dump behind the cab like i have it but the headers are gona make a diff the ones i have now are POS and also i got my cousin to hook me up with the strait stainless from his muffler shop lol free that stuff is expensive lol

[Longhorn Man]

I would take it back as far as I could if I were you, and if you can, get it out from under the truck. The exhaust fumes are highly corrosive and can mess up the sheet metal back there.

[ClassicRedneck05]

right now its dumped just under the bed past the cab a lil the mufflers are long also

[409biscayne]

2 1/2in is plenty big , that's what i run on the 68 w/ 396 dumped over the axle housing , works great . At one of last summers sat. nite drag races i opened up the headers and lost 4/10ths thru the 1/4 , lol sounded cool though . Unless you have a razoo motor you don't need 3 inch . Just my .02 .

[matthufham]

alot of new trucks run a y pipe with 2 1/2" pipe all the way back, so they push 8 cylinders through 2 1/2" pipe. you want to push 4 cylinders (4 per side) through 3 inch pipe?

i saw u wanted those bullet mufflers, they're loud glass packs in a sense, so if you want loud, then that 3 inch pipe will help there.

[ClassicRedneck05]

Originally Posted by matthufham

alot of new trucks run a y pipe with 2 1/2" pipe all the way back, so they push 8 cylinders through 2 1/2" pipe. you want to push 4 cylinders (4 per side) through 3 inch pipe?

i saw u wanted those bullet mufflers, they're loud glass packs in a sense, so if you want loud, then that 3 inch pipe will help there.

i already have the bullets i LOVE IT

[jerry moss]

i work in a muffler shop (22 years) and i get this question about 3-4 times a week. i always ask if they're running 700+ H.P. and always get a dumb look and a " no it's stock 350,327,283etc with a mild cam,etc." i tell them running 3"duals on a stock/mild motor will kill all low end power--it looks cool but it's a waste of money. unless you're running an all out drag motor--you need some backpressure on a gas motor. got a diesel---open that sucker up !