[j.fro]

I use the same technique that thstone has described, varying around 3-4K. You've got to feel it out during the first two runs to get it right, however. On cold days or slick tracks, I'll drop the revs down to keep from spinning and wasting time, but on hotter days or stickier tracks, revs can get pretty high to not bog the launch.
When my 6 speed was opened up at 142K for a 2nd gear pop-out issue, the gears themselves looked great. I've heard of lots of 5 speeds handling pretty impressive power from 3.4/3.6 engines.
Be sure the axles are nice and tight. I've heard about more problems there than with the transmissions.