I also thought about that but, it only takes a few seconds on the ground to get the temperature up that high and when in the air it was flying for 8 minutes, anyway in those few seconds on the ground the difference was still 35 degrees and just like in the air it was the left side that was hotter. I will post a few more pictures when I have more time.

Approximately half of the lower cowl is removed, I originally had a 3W-80 single cylinder engine in this cowl, so it is open pretty much from the back of the carburetor to the firewall.

Is it possible that I am getting some air sucked in from the bottom of the cowl and because of that I am not getting proper airflow from inlet to outlet?