I've been running the middle sized Comp Thumpr in a 273. With 1.75 headers 3in collectors with street tunnel ram and pair of 450 cfm Holly's. My car is around 2600lbs with a 4speed with 4.56 gears and currently 29in tall tires.
That Comp Thumpr has been a good cam for my only 9:1 tween. Car...