The drain back valve is irrelevant here. The filter is upside down. If the tube is eliminated, then the oil will drain back through the galleries and ultimately into the pan. What's the big problem with running the correct filter?
Ok,that's what I thought. So, without the standpipe the pump needs to fill the filter before anything goes to the engine?
Now part 2 of my question. On a '75, I am 'assuming' I have the shorter standpipe. Is there any issue having the shorter pipe with the longer filter? Is it still waiting for half of the filter to fill with oil on start-up? Or will it start to push out what's there immediately?
