I did a 2.5" in 3" out the body just in front of the passenger tire with shorty headers amd a flowmaster 40. I lost a lot of bottom end from my mild 351W with a 4V Edelbrock. Until I decided to tune it. Man the timing changed alot, I had to advance it quite a bit. And the carb was running way too rich. After I got the tune right for the new exhaust I got my bottom end back, and I gained a lot on the top end. I recommend the super single, but be sure to re-tune that motor afterwords!