call those caddy parts guys and see if the eldorado oil pan will let a 472 fit in there.
i have been trying to sell my 472 for months for $500 and now $450 and cant give it away. they are all over, and just going to waste. would be a million times better than what you got now, unless your motor is in good shape, which is the only reason i would keep it.
after re reading your op, just keep it stock, w minor upgrades