This is a photo of a stock full flow 261 with the factory filter.This engine was originally pulled out of 62 big truck.The feed port to the filter on a full flow engine is the lower front oil port.The return line goes to the rear oil port.This engine had no place for an oil guage, notice where I tapped the filter elbow for the guage tube. My other full flow 261 uses an after market spin on filter set up.Theres a small dowel near an oil port, that supposedly must be in the "out" position to open a internal bypass if the engine is going to be run filterless.
261 filter
