SEAN HYLAND MAKES CAMS FOR THE MODULAR ENGINES. THERE ARE DIFFERENT GRINDS FOR THE AUTO AND MANUAL TRANNYS. KEEP IN MIND THAT YOU HAVE TO GET 2 CAMS, ONE FOR EACH CYL HEAD WHICH MEANS MORE MONEY. AS FOR HAVING TO GET A MODIFIED COMPUTER PROGRAM, IT IS NOT A MUST, BUT IT WILL DEFINATELY BRING OUT THE TRUE POWER GAINS. MY ONLY QUESTION IS THE INTAKES. THE MUSTANG AND TRUCKS HAVE INTAKES DESIGNED TO MAKE POWER IN DIFFERENR RPM RANGES. THIS IS A CONCERN BECAUSE CAMS FOR A 4.6L ARE MOST LIKELY DESIGNED FOR A STANG.