The early Chevys and GMCs, up to '62, bypass filters took oil from the main gallery, filtered it, then returned the oil (thru' a restrictor) either to the rocker arm shaft or a fitting in the crankcase. The later Chevy 261" had a filter that could be used either as a bypass or full flow.
With the '63 and up engines having full flow filtering, why don't you just use them to filter all the oil?
Tim
