I have been doing a little research on Donaldson Endurance Oil filters and have found some on the Donaldson site that have a 99% Efficency at 15 microns. I have got a 3/4-16" filter base but can't find a Donaldson Endurance Oil filter with 3/4-16" threads. I am wanting to make a filter setup for my transmission on my 1994 Mercury Sable 3.0 Vulcan. The tranny is a AX4S. Right now I have a Frantz Transmission adapter installed on a cooler line and a Magnefine 3/8" filter in place of a TP filter. So I am wanting to find a filter thats not a TP style to instal in place of what I have right now. I was almost thinking about a Hydraulic filter. I'm thinking it would be a good idea to install a Magnefine filter after the spin-on filter because of the Magnet advantage. I would be willing to buy a filter base if I had to so I could run a good size Donaldson Endurance. So does anybody know what would be a good spin-on style filter for my application?