I am VERY happy with my combo! The only thing I would do different is to get longtube headers, which is what I am going to do soon. I have found some Mac's that are barely used and I am going to get those. Other than that, I am pleased with the P's. It gave me quite a bit of an increase. I don't have any numbers to back it up right now, but my SOTP meter says it is quite a lot. Longtubes take an H pipe that is made for LT's, but they are usually interchangeable with other headers, unless Flowtech makes them so that they only work with their header. Central Coasts deal on heads/headers/intake/roller rockers is a pretty good deal if you have the money. Plus, you figure the P's + new exhaust will be around $800 - $900 for the whole thing. The Ebok's will cost you $1000 just by themselves. The main reasons I went with the P's are because of the great power they make and the cost. Plus, I only had stock headers before so new headers wasn't an issue for me. Also, by getting the P's it allowed me money for a cam, which I really wanted.
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1991 Mustang GT - Cobra Intake, FMS 65mm TB, C&L 73mm MAF, GT-40P heads, Crane 2031 cam, Crane 1.7rr, Built AOD, Art Carr 2400 non-lockup converter, Transgo shift kit, BBK chrome cold air, FMS 'P' headers, Pacesetter off-road H, BBK aluminum pulleys, 2-C Flows w/ dumps, 4.10's, Steeda STB, for now...
The Original GT-40P Tech Page