Most use the Johnson as a direct fit. Call Tom at Sport Machines he can hook you up. Not sure of the flow rating on the stock one. In addition I am not sure if the Shurflo is a direct fit might have to change some things around for it to fit. Fat Nat (Jeff) has a old ATR setup for sale on here (hit him up). Still haven't got mine to cool down yet as my Temperatures are way to high however my block is 3/4 filled and don't have provisions for an oil cooler like a stock block.