225 head pipe

George Jets said
Unfortunately just opening up the exhaust system on a slanty is not going to wake them up from the dead.

Unless you go high compression and cam like Rusty did.

Had the '78 225 factory 2 bbl setup and the '76 225 1bbl with the best factory cam. No comparison when going to stock 318 with a 4 bbl. Night and day difference, I know I tried. 2 totally different vehicles going from a slanty to a V8.

Wish it were different, the slanties will stretch your mpg though.

☆☆☆☆☆

Sigh, another V8 guy that doesn't know how to tune a \6. When we were racing, the biggest improvement on my wife's stock '73 Duster was installing a 2 1/2" exhaust system. The second was a shift kit in the 904. The third was a super six manifold with an Autolite 2100. The bigger exhaust and intake allowed the engine to breath. The shift kit allowed the transmission to shift correctly to take advantage of the other changes.

This allowed that Duster to run a mid 11 second 1/8 mile. And this was with 2.73 rear gears. Not bad for 225 cubic inches of raw power.

On our current '74 Duster, we are running 3" exhaust from the T-bar support to the bumper. Off the manifold it is 2 1/2" tapered to 3". And the manifold has been port matched and the outlet has been opened to 2 3/8" and yeah there is a noticeable difference.