I have hesitated to put my 2 cents in, but,(you know me, I can't shut up) if you have a '58 or later block the full flow filter was an option, there are 2 larger oil outlets on the drivers side, one on the lower galley and one higher up. Just above the lower one (which is the pressure side) there is a plug, or whatever, that if it is flush with the surface renders the block to be a bypass filter system. If the plug has been driven in to block the transfer galley it is imperative that the full flow filter is in place. The lower one is 'IN' and the upper one is 'OUT' I sold a High Performance '62 261" to someone who thought his buddy's opinion was better than mine and seized up in about a block.
Just sayin'
Tim
