On stock timing, I wouldn't go more than a 50 shot, maybe 75. However, if you take out some timing you can run 150 shot all day long. Some people have done 175 on the stock block, but that's pushing it a little in my book.
__________________ 06 Cts-V, LS2, stock for the moment 94 Z/28 GTP Stage 3 heads, 230/244, .510/.540 112LSA. Built-T56, Nitrous Oxide, all bolts ons, etc. 91 CRX Si w/ B16 swap, nitrous fed daily driver.
You can go as high as a 100 shot on stock lt1 without having to pull anytiming, but I would recommend atleast getting colder plugs and gapping them accordingly. In order to go up to a 150 shot I would recommend pulling some timing (approx. 6 degrees) and upgrading your fuel pump just to be safe.
I started spraying my stock lt1 with bolt-ons like 3 years ago when it had 100,000 miles on the clock and I havn't had any problems. The car now has 112,000 miles on it and I'm still spraying the **** out of it
You can get away with 100 shot without pulling timing i'm sure, but run the TR-6 plugs gapped at .035 & it wouldn't hurt running a 20/80 (20% race fuel) mix off 105 Unleaded just to be safe with the stock timing, thats what i would do.