Just a suggestion.....I'd check my oil pressure on your 57 engine before you add the by-pass filter system. I found that the bypass system bled of 5-7 psi of oil pressure and it didn't seem feasible to divert pressure from the mains to pump 10-15% of the oil through a 1950's technology filter. Granted, the 235's don't make/need a tremendous amount of oil pressure but if an engine was in the latter stages of it's life, the extra 5-7 psi might be needed. Changing oil at 2000-3000k seems easier than changing out a set of engine bearings.
If you're running good oil pressure without the filter and can afford the accompanying pressure drop, you could add it on. Your call!!!
Dave
