I'm not particularly fond of doing the "full flow" modification to a stovebolt engine. With the right kind of bypass filter, the oil gets more, and smaller particles of debris strained out- - - -it just doesn't happen all at once. A full flow filter has to have filter media that's open-weave enough to allow a high volume of oil to pass through it- - - -enough to lubricate the engine properly once it gets through the filter. For that to happen, it must allow some of the smaller particles of debris to pass. I'm in favor of filtering oil a little at a time, and doing it with a filter media of around 1 micron. That's approximately the size media that's used in industrial hydraulic oil filters, or maybe Diesel fuel filters. To strain oil that well, the volume must be pretty low. A bypass filters system bleeds off a small volume of oil, sends it through a 1/16 inch restrictor orfice to avoid oil pressure loss, filters it efficiently, and dumps it back into the oil pan, or in the case of a spray oil engine like a 216 or early 235, sends it to the rocker arms. All the oil gets filtered eventually, just not every time it cycles through the oil pump.
Millions of stovebolt engines were sold with no oil filter at all- - - - -a filter was an extra cost option sold by dealers. That's why stovebolts (and other car makes) used flex lines to and from the filter- - - -it gave dealer mechanics a few options about where the filter got located, and gave a flat rate mechanic a quick way to install a filter after the car was sold, before it was delivered to the customer.
To make a stovebolt engine (except for later model 261s) a "full flow" filtered item, an internal oil passage must be plugged between the oil pump and the main oil gallery, and at least two holes must be drilled and tapped into the block. That's best done during a complete teardown to a bare block, so all the drill and tap debris can be thoroughly flushed away. It's not a project to be attempted by someone who does not have a very thorough understanding of the stovebolt oil system.
Jerry
