I've got to chime in about the warranty issue, guys. My dad went thru a warranty issue on the 302 in our old station wagon. Neither Ford nor the dealer has to prove anything, they just need to show that lack of proper care & maintenance, modification or something similar was "a likely contributing factor" to the problem. It then becomes your job to prove otherwise. If you need to hire alwyer to do so, do you think they will reimburse you the legal fees? Take the driveshaft issue: lets say a year after putting the new one, you take your car in cause the TR3650 is giving you some problems. The dealer sees the aftermarket driveshaft & says something like "The different rotational mass caused premature clutch wear in the tranny & your warrranty doesn't cover that." Right or wrong, it becomes your job to fight them & prove otherwise. I've seen it happen. That's why I'm having my dealer install FMS 3.73's & getting a letter from the dealer stating the upgrade won't affect my warranty because it was done with Ford parts, Ford fluids & Ford technicians. However, any other dealer wouldn't have to abide by such a letter, because it was written by a dealer & not Ford. It's a convoluted system & you really need to consider these possibilities.