I have an 97 Ls with a fmax turbo, had the thing running for not even 30 minutes and having problems... pouring out smoke, oil out the exhaust and the air breather (blew the stock head gasket), installed the low compression head gasket but still my compression reads 70,150,70,60 so...it has got to be the piston rings, so this is probably a costly install so should I just buy a new block because there fairly cheap for my car?

 

it will cost just as much or more to install a new block besides, I wouldnt put a new motor in my car without replacing the piston rings first. Either way you wont get out of replacing the rings (if you do it right).

 

you could but you won't know the condition of those rings/pistons.
If you have the money why not build the bottom end while it's out?
I would opt to replace the rings instead of buying a new block