Dyno testing a stock(?) 1972 440

when removing the so I thought was the stock cam I found a mopar purpleshaft from what I could tell was the mopar bb 430ish lift cam. went ahead and installed the bullet cam and got it tuned in started g-tec testing and the truck has been roughly 2.5-3 tenths slower i'm back in the 16.30s , so I put a 750 double pumper and the truck seams to like it but the times are no better and little lazy when towing also does no tlike as much timing as before sorry for the slow reply