I Have a 98 5.2liter v8 its 2 wheel drive and i have never had a problem with it untill i got bigger tires i went from 245/75/r16 to 275/75/r16. Now it has no power and it shifts rough i thin my gears are being messed up but i do not know the stock gear ratio or what i need to change them to if this is the problem at all.

 

i think bigger tires = more speed but harder to turnthem and get the truck rolling... so probly gear it

 

on the inside of the drivers door there should be a sticker that tells you what size tires you "should have". i think thatmine aresupposed to be 225. i also experienced a lot of power loss after the new tires. gas mileage sucks too. instead of miles per gallon its more like gallons per mile. its all good though. i'll just make it more powerfull and change the gears from 3.55 to 4.10

 

bigger tires = looks good = more rolling resistence = faster ground speed (where shift occurs) at lower rpms = less torque, yea it sucks. the 4wd's are typically 3.55 gears, check your rear axle tube drives side for a sticker should tell your gear ratio if its still there. not much you can do except turn overdrive off for city type driving or spend money changing rear end gears.