Use both systems if you want really good oil filtration. The full flow system has to have a filter with a sufficiently open weave media to flow enough oil to keep the engine lubricated. A bypass filter can slow the flow down and strain out the particles that are small enough to pass through the full flow media without slowing down, let alone getting trapped. The main function of a full flow filter is to strain out the particles big enough to do damage to the engine before they get to the bearings. In an ideal world, an engine would come with both systems, and that can be done on a stovebolt engine by anyone with a little time, money, and ingenuity, even on the engines that didn't have the capability for full flow filtration from the factory. 235's and early 261's need to get some internal modifications to the oil galleries to allow a full flow filter to be used, however.
Edit: Try this experiment- - - - - -brew two pots of coffee- - - - -one by putting the ground coffee into a (clean) athletic sock and repeatedly dunking it into a pot of boiling water, and the other by dripping the water slowly over the grounds through a regular piece of filter paper. Which cup of joe will have the most sediment in the bottom?
Jerry
