I just picked up an Edlebrock performer intake, i will be replacing my Cobra intake on my 94 GT. i wondered if i would be wasting my time until i put better flowing heads on the car. the cobra intake is the only mod i have done along with 24lb injectors, and the MAF to go along with it. when i do the swap i will be deleting the smog pump and everything with that as well as bolting on BBK equal length shorties. so would it benefit me to put the performer intake on now? or wait until i get heads. Also what is an authentic Cobra upper worth? its in good shape, has about 10k miles on it. i have an explorer lower with it, i figured that was worth about $50... any help is appreciated.