Summit 408 Short Block??

Not a LA block, can't use LA heads.

I agree. Even more so that I have a bunch of LA heads.

BUT

The remaining head selection is;
Any Magnum style head.
Stock heads - R/T - MP had a cross over head as well. Not sure if that would work.
EQ/RHS
Edelbrocks RPM
W2/TD machine rockers with oil through pushrods. I'm not sure if there is another manufacturer that has oil through pushrod to the rockers.

Not a bad selection of heads at all. Not one bit.