Engine for 1991 Corvette

I was hoping someone could give me some useful info on finding a suitable engine replacement for my 'vette. I have a 1991 Corvette with the original L98 engine. The engine block is cracked and is leaking engine coolant into the oil reservoir, sooo now I'm in the market for a
new engine.

Question is.. what engines will fit into the 1991 chassis ? I've been
told only 2 engines will fit but not sure if thats true. Any info would
be greatly appreciated !

Fyi . Not looking for any rebuilts, looking for a new one i can drop in

Thanks !