Overheating problem help appreciated

I put on new cylinder heads and now my head temperature gauge says I'm running way too hot. I'm going to list the changes I made to this motor and if anyone will take the time to read it and give me some input it may save me a lot of trial and error. Thanks in advance. I rebuilt this motor last winter using a GEX rebuild kit(new p&c, reground cam, reground crank, reconditioned rods, reconditioned lifters and new bearings) a new AS41 case, rebuilt Mofoco heads off a low mileage donor. At that time it had a 34pict3 carb and 009 distributor. I adjusted the compression ratio to what should have been 6.7to1 using .020 shim under the barrels and .060 aluminum head shim. It has all German cooling tin and working thermostat. It ran okay but idled poorly and ran a bit hot on the highway. Someone gave me a new 30/31 carb which after jetting in helped the idle but still ran a little hot. I got SVDA distributor from air cooled.net, that helped a lot. Still ran a little hot, about 350 on the highway I'm sure about the jetting and timing so I figured maybe lowering the compression ratio wasn't such a good idea. I rebuilt three air cooled VW's and never adjusted compression ratio before, all of them ran fine no overheating. I've installed two rebuilt motors for other people that did not have compression ratio adjusted and they also ran fine. One of my valves kept tightening up so I got a set of new stock heads, and removed the .060 head spacers, while I was at it I put in an alternator and new air cleaner with air preheat to stop my carb from icing up and a new stock German muffler and oil filter/pump from air cooled.net. After these changes I'm getting dangerously high cylinder head temperatures. I checked timing several times and rejetted the carburetor. According to my air fuel ratio gauge even my 120 main jet(which is the smallest I have) is running too rich and a color tune test and plug reading verified this. I have gone over and over the cooling system and everything is working. Oil temperature and pressure is fine. The only thing I can think of is the compression ratio could be too high, but with the 020 shim under the barrel it should be no more than stock. I'm running high test gas. I tested my head temperature sender and it's only about 20 degrees off. It's currently under the #4 sparkplug. The highest head temperature I've got was 500 degrees on the highway, I know this is a wreck your heads kinda temperature. Weird thing is it was running fine, didn't smell like it was burning up, in fact if wasn't for the gauge I wouldn't have known it was too hot. That's why I tested the sender. Putting my hand on the intake manifold and on the heads I can tell they are running too hot, but maybe not as hot as my gauge says. The only other thing I noticed was after installing the alternator there is about a quarter of an inch gap between the fan and the fan shroud where the air enters, I never noted such a big gap before. I've never encountered a problem like this with any other air cooled motor. In a seemingly unrelated problem twice now since rebuilding the bottom end I have hit 80 mph for very brief periods(less than one mile) both times I got a gush of oil from around the main seal but dosnt leak a drop any other time, also it sometimes shudders when letting out the clutch, the proper boden tube helped but didn't eliminate it. Could that be a crank turned out of true? After all I did get it from GEX. I know I'll find the overheating problem sooner or later, but with some input maybe I'll find it sooner rather than later, thanks again.