Eric and I discovered today that the combination of the Mocal thermostat, Champ oil pan adapter, and JRS Tri-Y headers is not going to work.
It seems that the tri-y headers are tucked closely to the block, which is good for clearance, but bad for my thermostat.
So I'm back to trying to find a good solution here. I may have to go with something like JCG's remove filter adapter (if I can) to mount a remote filter, but that also means I'll need a remote thermostat.
Very disappointing, that Mocal is a nice setup! If I can't find a good alternative, we may consider cutting and rebuilding the tube of the header which is in the way. Of course, the headers are already coated, so that's not a great option either...