Battling overheating new 360 build

Just finished putting a rebuilt 360 in my car. The motor runs great, plugs look good, but I've been fighting an overheating issue since the motor swap that I didn't have with my 318.

When idling, the car will run all day, no problems. It's when I'm driving that the temp will work itself all the way over to the hot-side of the dummy-gauge. I have to pull over or park and within a few seconds the temp will drop back down.

I have a 22" radiator and the factory shroud. I'm not running a clutch on the fan, however I have the factory 6 blade fan installed.

One thing I did notice was that the fan was about 2 1/4" away from the radiator itself. I purchased a spacer to get it closer to 1", but I'm unsure that's going to solve my issue.

Pic of the plug, car might be running a touch lean, but nothing out of control. I am running 38 degrees all in and have the vacuum advance hooked up. Maybe I'll try running without the VA and see if a little less timing helps the issue?

I would think that a 22" radiator and shroud should be able to cool an average 360.

plug.jpg