If you are not worried about the weight, and needing an all aluminum combo, a truck 5.3/6.0 can be had pretty cheap! (alloy head, iron block).
(The car versions are usually a little higher hp rating, unless you go pretty late model on the trucks)

An F body (Camaro, Trans-am) would be alot more common/cheaper than a GTO combo of course...

If you did go GTO, you could look for a later model one with a 6.0 LS2 as well...


You'll need engine mounts, headers, and oil pan/pickup... (and perhaps different front accesory drive stuff, depending on what combo you end up with)

Then just fuel system and wiring loom. Either modify a factory one, or plenty of off the shelf ones out there, along with a PCM flash.