wow looks like you checked it all
hows the motor mounts
some mitsu/cats when the mounts go bad the crank pulley drags on the frame maybe this is slowing the fan down just enough to raise the temp

vapor lock at the pump?
crack the bypass plug see if you get air

scale deposits in the block
clean and flush
a 1/4 inch of scale is equal to adding two inches of steel as far as heat dissipation
but i think the machine shop woulda tipped you off if they seen anything

i have found once or twice after some one changed something used RVT gasket maker and used way too much
one time on an LPG whos regulator kept freezing over
i found RTV from a previous repair had come loose in the water passages and lodged itself in the bypass fitting blocking water flow

just a few ideas hope it helps

i dont know how you could get bad timing without seeing other issues if no has touched the pump to date

after you remove it you need to flow time it