My 99 Gt has a KB blower on it, 5 speed, and 60K miles, I drive it up to my parent's place in the Smokey Mountains several times per year, it's a blast in the twisties with the blower (and Cobra brakes, IRS) on it. My F150 has 230K on it I drive it up there too. The only problems I ever encountered was a blown tire on the Mustang and (this was wierd) broken wheel studs on the F150 when I went to stop for a whiz break. Both times I dropped the vehicles off at a local Ford dealer and rented a ride, picked them up on the way home. total cost for both fixes was $425, less rental.
You can't beat a small town Ford dealer.

BTW some guy named Brian tuned the Mustang, it gets 23mpg on the road