Thanks for the comments Jake.
I reprogrammed my logger to flash an LED when the hottest temp from any cylinder reaches 375F. On a full acceleration run from a dead stop, gas pedal to the floor in each gear, 5500 rpm shift, #4 hits 375F at 4th gear, 3800 rpm consistently.
Thanks for the pics Wally.
In the diverter picture, it looks like you may only be getting 3/4 of the airflow from that quadrant as it looks like some air may getting past that last diverter to the left in the pic, if you compare it to the alternator guide diverter. I know you are using the 964 setup now though.
My idea is to use 3 diverters, one each directly behind the stock alternator ring diverters and one in between to make 2 channels to capture all of the airflow of that quadrant of the alternator ring. This will mean changing the positions of the factory alternator cap diverters.
The factory alternator ring diverters look to be of an airfoil design and I will try to incorporate the airfoil shape into my diverters placed on the alternator cap. I will keep placing diverters around the alternator cap, taking more air from each neighboring quadrant on the alternator ring until I can equalize the temps. That is the plan anyways !
Who knows if it will work until you try it.
Sandeep