the bypass relief spring just opens and oil bypasses the filter cooler with the stock stuff, 1/2" is #10 I used aeroquip twist lines

borgie my pressure on a stock 502 mag ranges from 20 -40 should I make this modification?

Teague makes really nice filter mounts (billet aluminum) and they feature 3/4 npt ports that you can reduce to -10(ie 1/2 inch). I was using a different brand prior and was not impressed with its quality. A member on here turned me on to the Teague stuff. Very high quality and look awesome in black anodized finish.

Block adapter: http://teaguecustommarine.com/smartt...off-gen-v.html

Filter mount: http://teaguecustommarine.com/smartt...-npt-left.html

I also am using the Teague billet fuel filter mount for the FST brand fuel filter. FST is one of the best, so keep that in mind if you eventually upgrade your fuel system.

Is your 502 stock? It wouldn't hurt to upgrade to -10 especially if you plan to add horsepower in the future. Keep in mind that the lower pressure could be a erroneous reading(you need to verify actual pressure with another gauge on the block). And the engine could be getting tired. However I've seen quite a few 502's with that oil pressure and they were fine. Everyone blindly prescribes the 10psi per 1000rpm. That is old thinking and doesn't accurately tell someone if their engine is in the safe range. IMO 20psi hot at idle isn't an issue. However, if you are overheating your oil, that is a bigger concern. Verify oil temperature as well.