Ronbo, that's easy, because an older block has soul. Hog wash an older block is any more risky than a new block. Either new or old, if it aint checked out and finished properly it will bite you. I've seen the pictures of a Shelby block with a rod sticking out the side. New anything offers no gaurantee it will always be perfect, there is risk, no matter how you cut it.
If I couldn't find a decent side oiler block, I'd go Genesis, keep's the cost down and either way is an excellent choice from a ROI point of view. Shelby block? Eh, nice call, but I don't think it will return enough in re-sale to warrant the additional expense. Now if your buying it because YOU want to have one, thats cool.
428 is not an option unless your really strapped for cash, then what the heck, consider a 390!
