I was unable to find the answer with the search engine. Are there different outlet sizes on the exhaust manifolds for different engines or model years? If so, which ones have which sizes? TIA Wayne

The only change is the headerpipe/exhaust pipe... Feather Duster/Super Six/etc.. just have a larger tail pipe attached to the stock exhaust manifold and is better matched to the actual opening...you can have one honed out if you need that extra 1/8"... but that isn't worth the money over other improvements that gain both power and mileage...

Also the choke pulloff pocket changed over the years, so if you change from an early one to a late one, you'll need to engineer something to work, or find the one year only transition pull off...

Good Luck,

-D.idiot

Excellent, just what I was looking for. Do you happen to know the size of the standard outlet then? I need to make up a pipe.

Stock 1 barrel pipe is 1 7/8"
Outlets are 2" +/-

"Feather Duster" Exhaust (best for mileage and a smidge of power on stock engine), 2 1/4" pipe...

If making whole new pipe...just upsize to 2 1/4" to the muffler and 1 7/8" or 2" out the back...

-D.idiot

Thanks again for the info. I'm building a J-pipe for a turbo and wanted to match the outlet as close as possible.