I retired from racing this year, and sold everything. Since I had an open trailer and my pickup truck was my daily driver, I had to load/unload everything each trip to the track.
I had a tote that had engine gaskets, oil, filter, ATF, brake cleaner, other fluids.
Another tote had spare starter, fuel pump, pushrods, spark plugs.
2-drawer tool box with hand tools, a plastic box with all carb parts and gaskets, another plastic box with electrical wire, connectors, zip ties.
Generator, battery charger, extension cord, 2 fully-charged jump boxes.
For a Saturday night race, a 10 X 14 cooler was sufficient. A weekend race requires another large cooler full of ice.

I gave the two track-day totes to the guy that bought the car.