E303 won't work with speed density (don't know what year you're running) and with mass air, get the idle air kit. GT40P will require new headers as they don't line up with stock Mustang. Check about using 1.7's....they're probably ok, but IMHO, I think they're a lot of money for little effect. I have an explorer engine with the older GT40 heads and had to go to mass air with the E303. Good combo.....and cheap.
He's good. I was there this past Sat. I held a McClaren Super Head in my hands, the best head ever made for a Ford Windsor engine and was ogling an all aluminum 351W stroked to 427 with a Kinsler fuel injection system converted to EFI. Had 8 huge stacks bolted to the TFS High Port heads intake runners. Truly a work of art that is going into a FFR Cobra Replica that is going road racing.
He can get anything you need, even hard to get stuff that has been discontinued for years new in the box. Like my MAC/TFS High Port 1 3/4 in lontube headers for a 302 block, these have been obsolete for years.
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