Burnouts, posi rear, ~33" tires? Will the 8.5" rear end, if that's what you have, like that kind of misbehavin'?
Is it a 4x4? Then don't forget about the 8.2" IFS front diff gears; you'll have to pick a ratio for which you can find gears for BOTH diffs.
When I changed my diff gearing I picked a ratio to yield a reasonable engine RPM at speeds that were usable in both 4th (OD) *and* 3rd. My thoughts went like this: I figured that I would use 3rd if I was towing a heavy load, and I wanted to keep the engine RPM at or below 3000RPM at 65MPH in that case. Without a load, I wanted to cruise at 70MPH with the RPM in the range of 2200.
In your case, it appears SWEETK30 (above) determined that a 4.56 ratio gives values that I feel would be best (for me anyway, YMMV).
My $0.02.