this is a stock block, fitted with 4 bolt billet caps, sleeved to 4.00" for the class, and sleeved lifter bores. no, the oil does not go to the front of the block. unfortunatly, the guy who built this died, and the guy i bought it off of bought it from the builders son, so there is no way to pick the builders brain as to what he was trying to accomplish. the oil filter return (pipe nipple) is now where this guy had the oil pressure line...very odd.