It has more to do with weight and torque, what works on a 2500lb vehicle wont last for $hit in a 3800lb vehicle, plus there wasnt a bigblock made from the factory that didnt have the bigger 12 bolt carrier.
My buddies has a 71 nova, 496BBC he's broke countless 8.5 gear sets, and he has the billet caps, studs, aluminum cover, after market axles the whole nine yards. He was finally convinced to upgrade to a 12 bolt after the last set only lasted 3 weekends.
But on the flip side - I have a buddy who has a fully narrowed 8.5 ten bolt in his tube chassis 68 firebird w/ 427 sbc that runs 5.90's all day long w/ short times in the low 1.30's, he's never had a moments trouble out of it, not that I would have done it but its just an example.
I think yours will be fine at your Hp level and weight, when your money gets right > stick a DANA 60 in there and forget about it.
Goodluck, Cp

I just learned somethin'

you and me both espically in this forum, Thank you everybody and your comments, I have had a couple people come over and look at it, it has richmond gears and they look heavy duty, there are scars on the spiders and the ring gear but my buddie said the pinion is set real deep into the ring gear, wich is a good thing, the wear we see may be normal racing wear, my pocket book wont support anything else right now so I am just going to clean eveything up real nice, use a good synthetic with the proper additive ( any suggestions there) and run it till it breaks, if it even does break, in the future I want to back half the car and run drag tires 15 or 16 wide, so until my pocket book can afford that I will run with my fingers crossed for this season. I am running on the car MT street drag radials and with the clutch pack in the rear end I am hoping that those 2 in combination will take exseive stress off of the gears.

You'll be fine don't sweat it, the last thing you need is to be worried about breaking something when your concentrating on a race, if it breaks so what, you can fix it.
You'll need some of that nasty smelling friction modifier stuff from the dealership, the stuff at autozone will not work.
It's about $10 for a 8oz bottle at the dealership and you'll need at least 2 to do the trick also use a name brand synthetic oil > costal or walmart brand lube won't cut it.
Goodluck Cp