Engine swap

I am thinking about buying a 91 corvette but it has a lot of miles not to mention it is not to powerful(for a corvette).
The problem is space the engine is almost to touch the hood as it is and I want to put a carberated engine in it
without putting a cal hood/
 
does anyone know of a company that makes a LS1 
 
Here is the engine I'm thinking abouthttp://proformanceunlimited.com/specs/350_420drop.html

Probably fit but might require a drop base for the air filter. 
 
Does Chevy sell a crate LS1?