ls1 oil changes...
51522 (Larger filter) - specs say that it filters 15 microns
51042 (Smaller filter) - specs say that it filters 19 microns
Here are the specs:
Part Number: 51522
UPC Number: 765809515222
Principal Application: AMC (82-86), GM, Saturn (93-08), Jeep (81-86), Isuzu (03-08), Saab (06-08)
All Applications
Style: Spin-On Lube Filter
Service: Lube
Type: Full Flow
Media: Paper
Height: 4.526
Outer Diameter Top: 2.921
Outer Diameter Bottom: Closed
Thread Size: 13/16-16
By-Pass Valve Setting-PSI: None
Anti-Drain Back Valve: Yes
Burst Pressure-PSI: 290
Max Flow Rate: 9-11 GPM
Nominal Micron Rating: 15
Gasket Diameters
Number O.D. I.D. Thk.
Attached 2.734 2.430 0.226
Part Number: 51042
UPC Number: 765809510425
Principal Application: Various GM Cars & Trucks (75-76) (96-08)
All Applications
Style: Spin-On Lube Filter
Service: Lube
Type: Full Flow
Media: Paper
Height: 3.404
Outer Diameter Top: 2.921
Outer Diameter Bottom: Closed
Thread Size: 13/16-16
By-Pass Valve Setting-PSI: None
Anti-Drain Back Valve: Yes
Burst Pressure-PSI: 320
Max Flow Rate: 9-11 GPM
Nominal Micron Rating: 19
Gasket Diameters
Number O.D. I.D. Thk.
Attached 2.734 2.430 0.226
Just thought some might want to know this. The 51522 IS A BETTER FILTER that does NOT impede flow!
Since this thread is back up....before people start bashing ALL kinda of Fram filters, the Extended Guard is actually getting pretty good reviews....seems to be well constructed and flows pretty well
Since valvoline came out with a synthentic for their maxlife line, I will probably switch the T/A over to it and give it a try since I rolled over 100k.
Never had a problem running conventional oil in a high mile car..still run it in my 233k camaro
I swear by M1/M1 now after reading the reviews on BITOG. I even put M1 5-30 in my snowblower!!

Like others have said here, a good education can be had over at http://www.bobistheoilguy.com/cms/
Last edited by bayer-z28; Feb 1, 2011 at 11:07 PM.
The Best V8 Stories One Small Block at Time
As far as the oil, I use whatever they have on sale. Usually Penzoil or Castrol 10w-30.
Well, sometimes if I want to get fancy, I use the AC Delco filter.
Last edited by highgear; Feb 25, 2011 at 01:29 PM. Reason: AC Delco filter
I wouldn't let that convince you, my factory ls1 blew and I pulled it apart and could see factory honing at 110k miles, and the people before me never changed the oil. Sludge was literally five Inches deep.
I swear by penzoil platinum and wix, but I wouldn't hesitate to use m1 oil and filter if penzoil platinum was out of stock one day..
Last edited by ncsu602; Feb 26, 2011 at 08:19 AM.








