I'd say if you like your freeway speeds and like the 4-speed then rebuild. That would be the easiest. If you would like to run with fewer rpm's then a T5 would be nice. I have 3:55 gears and run a T5 with 255 15's. I think I could go with taller gears but have not tried it so don't know for sure. The T5s come with a few different overdrive ratios that you might consider too.
Dennis
