Cylinders running too hot

That cam (292/508FTH) wanted a fair bit of idle bypass air on my 367, and a bit of idle timing. I was at 11.3Scr. And I was using the AirGap with a 750DP and TTIs.
Your throttles may be too far up on the transfers and so idling pretty fat. Then the charge may not finish burning in the chambers, but may continue burning in the pipes.
In my case the solution was to reduce the T-port exposure, introduce bypass air elsewhere, and bump the timing up to start the fire a little earlier. And I brought the Vcan in fast and hard.
I drilled the throttle-valves between the idle-holes and T-ports;about half way from the shaft to the leading edge. I started with 1/16"holes and ended with a 3/32" in each. IIRC 1/8ths were too big and I had to fill them in. This was in addition to the PCV.
My exhaust temps were not as high as yours, nor as far apart to start with; but they evened up pretty good. I found tho, that placement of the laser dot was pretty critical. Just a few millimeters could change the reading a lot. That's what led me to the still-burning theory.
Happy HotRodding