Personally, I prefer the filters that JATONKA recommends. His are true Diesel Truck Fleet high flow anti-drain back filters, not the big block chevy filters that the other guy is using.
Another factor is the size of the passage in the adapter that holds the filter base on and the flilter screws onto. The chevy filter threads onto a smaller 'nipple' and has a smaller diameter bore.
The bore if JATONKA's filter adapter is larger allowing a higher flow with less resistance. That may be a trivial difference to many, but since my truck is a sizeable investment for me, I do want to have the best choice for my lubrication system and a few dollars more is worth it as I see enough of an improvement in JATONKA's design.
I do not want to start a battle here, and there already are statements made in this thread that are somewhat slanted with no objectivity beyond price.
All I am saying is that I trust JATONKA that his adapters do what they should and I can get help and advice from John anytime I need it and he is a resource for far more than just Spin on Filter adapters. His experience alone is worth more than I can estimate.
I see the investment in JATONKA's adapters as being for more than just his kit.
You can do what you want, and I recommend you do your research as there are differences between these kits. I did my research and made my choice and I am very happy with the results.
RL
There are A LOT of different filters you can run on Westfolk's oil adapters. I DID my research (let's not publicly suggest I haven't when you don't know what I have done).
Lets not forget many people swap out the fuel filters for spin ons as well. Again, there are numerous options for filters. It ain't all about the oil.
For the primary I see no reason to put an adapter plate on there when you can easily swap the entire mount (as many folks do on their own).
When Westfolk tells me he has been running his design for many years on his work trucks, I beleive him. He uses his trucks in his business, not for a toy like I do. If they can handle what he is throwing at them, I'll be just fine.
I am NOT suggesting there is anything wrong with JTs stuff or he isn't a great guy. A few minutes with the search function will show that I have never said a bad thing about him or his product.
Nothing wrong with competition and free market. That's what makes America great. That's why I do what I do every day to help keep it that way.
Choices and options - no one should complain about having those.