for air bubbles in the coolant...i am assuming your radiator has a cap on it. what i do is fill the system up. then i fire the car up with the cap off. let it warm up then just keep topping off the radiator. once the t-stat opens up a geyser will shoot out of the radiator. top it off one more time and quickly cap it. then you should have absolutely no bubbles in your system. *note this only works with cars where the radiator cap is the highest point in your cooling system not including the overflow tank.

 

yeah, should you run the temp sensor off the intake at the thermostat housing? wouldn't that give an overall consistent measure? the heads get HOT when you are THROMPING on it i would think. if there was air in the system it would overheat at all times.
definitely have a fan shroud and air dam.

 

I went back last night and set the timing to EXACTLY 12 degrees BTC and that seems to have alleviated most of the problems. I took her to work this morning and thrashed her a few times for about a minute or so. She got up to 210 a few times, but nothing higher. We will see what the warmer weather will bring, bu I think it was all timing......however, now that shes at 12, its got some hesitation that didnt exist when I was running 16-18 degrees. (Or more, tab only goes to 14!) Can I tune that out thru the carb?