power gains from PI headswap and Vt stage 1 cams???

this cobra last i heard ran around a 13.3 in the 1/4 but that was wiht u/d pulleys, bbk throttle body, k+n filter wiht Pro-M MAF. I just checked out some specs on the 2001 lightning and it shows a 1/4 mile time of 13.7. Its about 1000 pounds heavier than my car is with me in it.