Tranny first gear combined with rear gear help

Hanlon and D&D transmissions sell stuff for the t-5 as well. Theres a g-force gearset for the t-5 thats still synchronized and can supposedly take 600hp and 500ft lbs (if you use their mainshaft as well)of torque without all the extra weight of the tremec tko 500/600(they dont like to shift if your really zinging) When I was into foxbodies I had a 347 and a t-5 w/3.73s and I blew the tranny a cpl times in the 3yrs I had that engine in the car (t-5z) with alot of passes on sticky tires (low 12s,high11s w/ 1.6 60fts) Get a good shifter for it like a steeda tri axe or a pro 5.0 shifter. I have a friend with a gt ragtop mustang street car runs 10.0s with the tremec tko600 and he had it faceplated in 2nd and third to make it shift right for him when racing, isnt really a mod for a regularly driven street car but it works.
Good luck.
Marvin