Let us know what happens. I would be curious to hear what happens if you change JUST the oil filter and leave the current oil in there. I am suspicious of any PH filters with good reason.
Well, at the moment I'm running a microgard MGL3985 because that's what I had, I pick up the new nipples tomorrow (one for me, one for wife), I think at present I have about 4-days driving on my current oil, for a grand total of about 200mi.
I checked the oil when I was out at the truck-stop off 395 and it's still as clear as the day I put it in.
I think all this "this filter is best and that one sucks" need some qualification. For example, a 50 BMG rifle is pretty bad ass, it will take out targets at very long range and punch holes in armor plate, and according to the guys in robo-cop, it will also shoot through schools. However, the rifle weighs 40lbs before you even put ammo in it, and when fired has all the subtlety of hitting someone in the face with a brick.
If you guys want, I'll put the fram filter in this week, and this weekend I'm driving up to norcal. I will take some photos of the oil, then I'll swap it out for the wix, and when I drive back I'll do the same? All you need to do is chip in on my gas bill!
Oddly enough I ran into the issue of the OFA 'nipple' being different threads between Renix and HO 4.0's just last night. I got an OFA off an '88 XJ at the junkyard hoping it might cure my leak (I've replaced o-rings on the existing OFA twice already and it still leaks), installed it only to find the new oil filter I'd picked up wouldn't screw on. I'm going to try swapping the 'nipple' back out for the HO one, but apparently I need to find an extra deep socket, mine is too short to fit over it.
Should the OFA on a HO motor be vertical or horizontal? Both of my XJ's (my current '91 and my old '87) have had it mounted vertical, but it was mounted horizontal on the '88 I got the new OFA off of. It doesn't look like there's really enough room to even get a stock size filter on and off easily if the OFA were mounted horizontally on my '91, and I like to run the larger 5.0L Ford filters as well. But since it keeps seeping oil, now I have to wonder if it's supposed to be pointing the other way...
When I started the thread, I was able to get on the OEM metric nipple with a 7/8" deep well I had laying around, it also looks like you could probably get on it with an open-end or box wrench without too much issue, however you might have to remove the OFA from the vehicle to accomplish this.
As far as your 91 goes, I would think sticking with the vertical orientation would be the way to go, the PH8A (common to ford), wix 51515, etc are the same diameter, just taller, which means it will be easier to get the filter out. I've always found the 3985 filter sits in there just low enough that you can't get a good two fisted grab on it to get it out of there and it's just low enough that you can't use a strap wrench either.
IIRC, HO is when they switched to the Standard thread from the metric and facing backwards vs vertical. I've been meaning to swap out the one on my renix so I can run a larger filter, but it works.
As far as whomever is complaining about how much the metric heep filter costs, the Napa Gold ones are very inexpensive. And the Napa GOLD filters are made by Wix, not sure about the standard ones. I believe that the CQ Blue are made by Wix as well.
My main complaint wasn't cost, it was more availability. Until I moved to washington I never went to napa, because the closest napa store wasn't on the way to or from anywhere I normally went, and getting there usually required passing it, and making a U-turn to get into the lot.
Oddly enough, up here in washington just about every farm store sells auto, tractor, and every variety of lawnmower/yard power tool part. It blew my mind the first time I walked in and not only found a new set of u-joints, MMO, but also all those high lift jack accessories I had always wanted/was too lazy to order online/didn't want to buy from 4-wheel parts.
