If you really want to do your Omega up right, look at doing an stroker engine starting with the DX Olds 350 diesel
block, converted to gas. You can't get a stronger block. I've seen a couple that were 442 cubes(nice coincidence, huh!) one with the new Edelbrock aluminum heads, one with the now rare Batten aluminum head. Both ran like a raped ape.
There is also a company called Bulldog IIRC that is making Olds aluminum hi-po heads.
Look to www.realoldspower.com
for info and links.