This is what the book said:
This is what all the flap is about, Motor City Flathead's Full-Flow Oil-Filter Kit (PN MCF-90-OFK). THis cut-away displa gives potential customers a clear idea of its form and function. The kit fits all flathead blocks and pans except the 1949-1953 Ford center sump, RIBBED passenger-car pan. In those cases, the engine builder will have to get the common smooth-sided pan. "What we've done is to modify the pump so when oil is picked up, it is re-directed through our special ground and heat-treated bottom plate. One hundred percent of the oil is directed out of the bottom of the pump through a bulkhead fitting to a remote filter. The filter can be mounted anywhere you like. The filtered oil is then returned to the engine in a direct route to the rear main and the main oil galley. We still use the same pressure-relief valve in the pump; we just go in the back door. We now have a moder