Sgt.Stinkfist

iTrader: (6)

im planning on welding a custom header back exhaust system for my 79. what size exhaust piping would you guys suggest for a stock port/street port 12a w/ a weber? im thinking anywhere between 2.25"- 2.75". tell me what y'all think is a good size.thx

Siraniko

iTrader: (13)

2.25 dual to one muffler. above that, it will be too loud. smaller will be too restricted. btw, there is big difference between stock and street ported 12-A. so which one is it.

1badFB

iTrader: (1)

wackyracer, those look like some huuuge honkin exhaust ports in your lil picture deely. im interested to hear about it if its yours but if it is just a pic from somewhere else no worries.

Sgt.Stinkfist

iTrader: (6)

i wanna make the exhaust system now, large enogh to be effective for use on a street port and later on i will have the motor ported, but i just want to get the exhaust out of the way and get some power out of it in the mean time.btw, any reason for smaller duals as apposed to a larger single?

85rotarypower

Use 2.25" piping. Anything larger than 2.5" is reserved for bridgeport/peripheral port or turbo. I went 3" on my car. Its a mostly stock 12A, no porting or anything like that. I have been told that I have actually lost power because of it.

comradegiant

2.25-2.5 would be my recommendation. 2.5 isn't so big that you lose power.

coldy13

one 2.5" pipe, or dual 2"

Sgt.Stinkfist

iTrader: (6)

thx for the info. i think im gonna go for a single 2.5", ive always liked the look of a large single tip(maybe a dynomax ultra flow) plus if the exhaust holds up over time i could use it for a turbo'd 12a