True about the 1 5/8" but ( as in my own case ) they FIT and they're cheap :-). My 414 runs 1 5/8 because I know they fit my unique chassis...and FAST cars run 9's and low 10's on manifolds and 2 1/2 " pipes


WIZE

World's Quickest Diahatsu Rocky (??) 414" Stroker Small block Mopar Powered. 10.84 @ 123...and gettin' quicker!

https://www.youtube.com/watch?v=-mWzLma3YGI

In Car:

https://www.youtube.com/watch?v=PjXcf95e6v0