I have been looking at the oil filter information on here and I had a thought. I wanted to pass it by you guys to see if I am thinking this out right. Now Purolator Pure One oil filters have a lot of surface area and supposedly good filtration. The worry with them is that there will be a flow restriction then right? Well if I were to use the bigger filter used on the Blazers that would increase flow right? So using a Purolator Pure One for a Blazer on my car would give me the best filtration with normal or better than normal flow.

I've been using the Walmart ST3980 (equivalent to AC-Delco PF 52) "Long" filter for the past few years with good results. I do not know the technical characterisitics of flow rate betweed the "short" ST 3387 (eqivalent to PF 47) vs. "long" filter. But I agree that I do get better filtration with the longer filter. The flow theoretically should be about the same although I have no physical proof other than the fact my engine has over 150K miles on it.

I've been thinking about going back to the standard filter. After switching to the longer one, my pressure has gone down and I'm a little concerned about it.

How could a longer filter cause your oil pressure to decrease? Even if it does create less flow restriction, that shouldn't change the pressure in the system, should it?

Yes a larger oil filter = less oil pressure in most cases.
The larger filter does allow more oil to flow thru it compartively and therefor less backpressure to the pump, where the pressure is usually measured.
Its been done before where unscrupulous individuals throw on a smaller filter to raise oil pressure...

The Wix version of the PF52 (Wix 51036) is actually a tad shorter than the PF52 AC Delco. Therefore, it'* a good mix between the sizes. I'm not so concerned with the oil pressure drop as the filter hanging down far enough to get hit by debris. The Wix is also a very good filter. I like the Wix (also known as a Napa Gold or a Carquest), the AC Delco, and for a cheapy, the SuperTech WalMart filter made by Purolator.

Unscupulous, as in shady mechanics saying they fixed a low pressure problem on someone else'* car?

When is the oil filtered, immediatly after it'* pumped, or after it goes through the engine?