early a-body (64-66 cuda or valiant) exhaust - H or X

I think I read in the direct connection racing manual about 30 years ago that the exhaust could be spray painted, where it stops burning off is where the cross goes. I could be wrong, or crazy.

I remember reading that as the way to figure out where to put a 'crossover pipe' on your dual exhaust way back when...but probably in Hot Rod magazine.