I have a 66 327 small journal that i am having a problem with. I have totally rebuilt the engine and now I can only get 17 pnds. of pressure at 2300 rpm. I have checked all the journals and everything else I can think of but no luck. I am wondering if it could be in the oil pressure release valve. And also If it possible to rermove the release valve without causing a problem. Also is there a tube of some sort that is supposed to thread into the block beneath the release valve where the oil filter attaches. Any help would be greatly appreciated. Thanks.