The thing is, I cant understand why you would want to drill a magnum block for head oiling holes anyways. I think early ones had the oiling holes already in them. Arent magnum heads superior to LA heads? I mean dont people put magnum heads on LA engines quite a bit?
Magnum heads are a nice improvement over stock 318 heads, or smog 360 heads. However, if somebody is looking for the rocker shaft assembly and more options for heads, the LA style heads offer all of that.