Yeah, I also believe a stock (= low) compression ratio will definately help to keep head temps down.
Somehow, I think that the high fan set-up of the FAT shroud might help to get the cooling air easier to the 2 and 4 cylinder; the air doesn't need to make a sharp turn, like with the deeper sitting fan assembly's.
I'am curieus what your take is on this Jake?
Thanks,
Walter
BTW, 275 F up a hill in a high CR 2270 is amazingly low!
BTW II, my stock 1,8 with stock cooling runs 325 F on the right bank and 375 F on the left bank all year...