Yea, Cal-vert is the common upgrade if Superstock ( SS) springs don't fix traction issues on a leaf Mopar, so I hear.
And I believe the 335hp was conservative due to insurance reasons from 68-72ish, I suspect a cam and better carb would net you an easy 400 hp, but you still, IMHO need 3.55 or 3.73 gears with the 4 speed....
