I have the 4.8, would it hold up to that kind of power?

 

With a turbo and some head studs and some thick ls9 gaskets you'd be there no problem and probably less money depending on what turbo you go with.

 

What about internals, or are the 4.8's beefy enough stock to hold up?

 

to make 600 hp they are fine, just upgrade to head studs and head gaskets

many yrs ago i made 700 rwhp on 16psi from a 4.8 with cam

 

bore and stroke the 4.8. 383 with ported 243s would probably work well with a blower cam shaft. probably 11-14k depending on if you do trans as well. I am in the middle of a build, the dollars add up quick. No such thing as cheap power.... except nitrous.... not sustainable.

Might be cheaper, faster and easier to turbo your current setup and be happy with what ever numbers come out. Might be surprised what a measly 400 to the wheels would feel like.