'The 383' ~ Getting Those True Factory Horsepower Ratings

69 Cuda 440 said
Yes, thru the Stock Exhaust System

Mopar did claim that you could squeeze out an additional {+6 HP} if you bumped
up timing from 35* to 40* Total Advance.

It's a start.. I'm sitting back,let others chime in.. ( makes it so much more fun..)..