750HP - RE; Pro gears - I'm no expert but I think it has more to do with the angle the gears are cut and the radius the teeth are. (more straight cut?) I didn't know pro gears are softer to. All I know is at ratios over 430 on a 9 inch ring gear there sure are a lot more smaller teeth and in my case the wear went away with the pro gears. Take DV up on his offer. If you don't I will pay a visit to his shop soon and we will have a community rear end out there!
Excaliber - Be carefull when buying this rear end as there are many styles of lockers out there that have close style names. To make matters worse the tru-trac is sold under several different names too!
cobrashock