my ladies 03 blazer requires the smaller filter but i switched hers to a
larger one from a s10. dont know why the dealer whats smaller filters
more oil equals more cooling.
i run the K&N oil filter with royal purple 5w-30 in my rig

 

The filters on the 03's are now PF 46's. PF 44 is no more. I'm kinda wondering about this because when I did mine this weekend and the damn threads on the new PF 46 were bad! Only threaded on about 1/4 way.

Had to run to Napa and they gave me a 1042 to go and it went smoothly after that.

 

So is the PF59 just a renamed PF58? I used to use the PF58 on my all of my LS1's, but this last time I went to get the filter there was no PF58, only PF59's.

 

PF58=no anti-drain back valve.
PF59=anti-drain back valve.

 

I would rather have the valve anyways, so that's good to go!! I was just worried about whether it would be an exact fit or if there was something different about the threads or holes. But I will be heading out today to pick up a case of PF59s for the T/A. Thanks guys.