I have a 90 pathy xe v6 128k. Am trying to do timing belt job (including all oil seals, tensioner stud, spring, etc...). I can find timing mark on crankshaft pully, but no mark on oil pump housing to line it up with. Have cleaned many times but see nothing. Pictures from this sight have shown oil pump housing "round" all the way under crank pully, but mine has a notch at the 6 o'clock position where bottom belt cover bolts on to. From what I see from on here and the manual it appears it should line up at 5:30 position? I need to know due to my cam pullies could be off by one tooth (found belt way too loose between cam pullies, drivers side dots line up, passenger seems to be one closer to tensioner than it should be, and tooth count seems to be off).
Just bought truck and put right in my garage to do all the repairs needed to make it road worthy for my drive thru the 'hood everyday.I like to do it once the right way so I don't worry about it.
Have checked this site pretty well and can't find any others mentioning they might not have oil pump "mark or notch" like mine. Any help would be great

Mine doesn't have it either. I think it's more of at the 5 o clock position. I've always done the tedious way of counting the number of teeths between sprockets.

40 teeth between the cams sprockets
43 between the cam and camshaft sprocket.

Nissan belts and I think the Gator brand at the autoparts store have the alignment lines painted on them.

Thank you for the reply. I think the left(drivers side) cam is off by one tooth due to slack between cam pulleys.I have left cam marks inline, right cam looks to be one tooth behind being lined up. It is just my best guess that left one is off without having two points that do align.
Just line up cam dots, install belt with lines painted on belt (this also did not line up on old belt), and count teeth? Then do two clock wise rotations to make sure?
Made sure tdc at distributor rotor, pulled valve cover to check lifters,and spark plug to see piston. Done belts in the past and always had three points to work with.Am I over complicating a simple task needing two points to line up to find which of the three is out?