A good rule of thumb is: 20-25hp shot/cylinder. So if you do the math, on the safe end, you're looking at a 150 shot....you might even be able to get away with a 175, however, at that point you're pushing it. Also, NEVER GET A DRY KIT. It leaves too much room for detonation and then KABOOM go the internals. With a wet kit, you're introducing the fuel/nitrous mix at the same time, so you're less likely to get a detonation from the nitrous getting sucked into the cylinder once the fuel has already ignited. I don't feel like writing a lot...if you want a more detailed explanation, PM me or what not. So, definately go with the WET KIT. The LS1s are a pretty stout block, so they can handle it, even with the slight overbore on select cylinders
*BTW: I Hate 10-bolts* ->Been through 6 thank got all on warranty.