I have a 2000 excursion diesel. I never owned an automatic diesel before so im used to just upgrading the clutch and building power without worries. My question is, how much power can my stock automatic trans handle? the excursion has 250,000 miles on it (i know thats alot but it was well cared for). The fluid is clean and does not smell burnt. The car was completely stock when I got it and looks like it never saw a trailer in its life. I want to do an intake, exhaust and chip. just for fuel economy... and to make it a little faster than my boss's f-150 :evil . I dont plan on injectors. I have a pulling truck for that. will custom tunes including a 140hp tune hurt my trans?