Has anyone else run into this?

I have 1991 Mighty Max and all the parts stores tell me I need a STP S3950 (example) oil filter but the one on my truck is a Pro-Tec 164 and it is way smaller.

When I cross reference the Pro-Tec 164 to STP I get S6607

https://www.oilfilter-crossreference...rt/PRO-TEC/164

I just thought it was weird.