I don't see the need for that cooler on a track car. That cooler sits right on top a the right side header, so I am not sure how much it is cooling. With that cooler deleted, all of the air goes to cylinders. I have not done this, but plenty of cars have and it apparently works. I like the idea of a filter on the pressure side. I am at the stage of full flow vs by pass and at this point in my thinking, by pass on the pressure side and full flow on the scavenge side. Tomorrow I may have a totally different rational, still trying to get a grip on how all of that plumbing works. A couple of scary stories about the pressure side filter collapsing and oil starving the motor, boom. I would like to avoid that. I have a System 1 cleanable filter that may be my answer. Jury still out.

What mods need to be done to the thermostat?

There is an oil flow diverter that goes in the place of the thermostat. Kinda like an IUD I guess.

You can also take apart the stock thermostat, remove the spring and element, and leave it in the open position with a sheet metal screw. Then you'll notice that one of the ports is always 1/4 blocked anyway with it wide open. Once you look at the inlet and outlet ports and compare to the thermostat, you'll figure it all out.