Don't you think I could get more wheel spin in 4HI than 4LOW? In 4LOW, with the 5.13s, I can't get over 6-7mph in 1st gear. I think I'm going to have to use 4HI and not let it get out of 2nd gear. I am going to try finding a siping tool to get some more depth out of the lugs, don't know if I can find the time to do it though. It will take forever.
personally i wouldnt be waiting to find out... if you have 600 miiles on your rebuild... you may want to go out and play... find different areas to test...
back in the day when i had 33's, open axles, 350, turbo 400.. i always used high... never had a problem.....
so you should go out and give her hell somewhere and test it out... try high, low, different gears like 1st, second......
the only true way to tell is your truck tested and proven....
you can take hp numbers, gear ratios and theories.. but to apply them with the driver you need to go find out....

thats all im saying... plus more time to play

Huh? LO5s were rated like 240hp and 300ftlbs stock. With flattops, and a good exhaust your should be somewhere around 275hp and 330ftlbs.
im gonna just state on my L05 block... so not sure how much different than his
out of a 1991 caprice 9c1 police car...
hydraulic roller cam - 195hp/295lb-ft torque
info from pg 5
http://www.9c1.net/brochures/1991/91_9c1.pdf

I'll send you a PM.