I respectfully DISAGREE on this, so..... do research, and call TG.
Not sure why crazypete is suggesting that........ transgo recommends drilling the seperator plate differently when you have steep rear gears, and using the hi rev kit to ensure shifts are right.......also, get the sonnax boost valve!
also, set the tv pressure right, or your downshifts will be crap. if the tv pressure is set TOO HIGH, it will take alot of throttle input to make the car kick down into the next gear, and this sucks ass when going up a hill in third (when have a lockup converter) and you need second, will alomost have to floor it to get 2nd.......I THINK this is crazypete's problem........also makes the tranny not want to go into od (tranny "thinks" the throttle is depressed further than it is, thus the shift into od is delayed, or will never happen.
last, if you screw up at all torquing the vb into the case, it will have all kinds of problems, migght not have a 1-2 shift, or might go into other gears too early etc...........get a in/lb torque wrench, and torque to 90in/lbs and take your time.