Muffler Flow

Old Tired Rebel,
The Walker Dynomax HEMI-sized (20" long) SuperTurbo flows about 70% to 75% of an equivalent sized straight pipe. and for the sound control they provide, this is fantastic.

I also wanted to add that they can be made to fit on A-bodies by just being careful of their placement and by using flanges to bolt the tailpipes on, if needed.
Tom