Most of the (is it 2nd generation they call these now?) Camaros that I see in my neck of the woods are white trash lawn ornaments or bonafide junkers unfit to be driven on a paved road. Yours looks like it rolled out of the showroom last summer; it is truly a beautiful car, and certainly worthy of another engine if that turns out to be the case.

Anyway, it sounds to me like you collapsed one or more of the pistons, and that will often happen when an engine is overheated. Be sure and check those heads real close, one of them at least (probably both) warped badly enough to need resurfacing, and maybe badly enough to crack between the intake and exhaust valve seats. Look closely for those cracks, they're almost invisible.

I'm just purely guessing and extrapolating from that; but, maybe when the piston(s) collasped it broke the skirt off one or more of them and they got wedged between the crank and block or a rod and the block or just somewhere in general so the crank can't make a complete revolution.

How to find out? Jack the engine up in the chassis (or better yet, pull it) and get the oil pan off. You will probably find one or more piston skirts in the oil pan itself. If not, at least you can see what's causing the crank to hang up. I definitely would not try to turn the engine over any more until you find the obstruction. You could BREAK the block, ruin the crank, bend a rod; things you don't want to chance.

As for the pistons and the bores, the pistons are probably junk, and the bores are likely scuffed so badly that your at least going to need honing to clean them up. If the block is already at .030 over standard bore, then you're most likely going to have to replace it as well, since it won't take much more machining.

In all honesty, I think you're probably going to need a short block at the least, and probably another set of heads as well. I've been in the very same situation with my '79 1/2 ton Chevy. A loose radiator cap (put in on myself) and 20 minutes driving to work one morning in July destroyed the left head and cracked the block (4-bolt mains no less) all because it overheated and I didn't even know it until I pulled into the parking lot at work and heard the radiator boiling over. I lost so much coolant that the temp guage didn''t register overheating, and I didn't hear the boilover because of my exhaust. I never even saw any steam or smelled the engine getting hot. Stupid, stupid, stupid, just didn''t tighten the radiator cap to the second notch after I checked the coolant level that morning!

Anyway, my truck is a rust bucket and it deserved a new engine.
Your Camaro is a piece of art, if the engine is toast. just shake your head and put it behind you. Your car is easily worth a couple of new engines. I hope you decide to fix it.