Mark,
I see what your problem is: you have 4 water temp gauges. That would confuse anyone!
Seriously, I put an automatic bleeder on the top right of the radiator in my '74. I used (if memory serves me correctly) a 6mm to 1/4" autometer gauge fitting. The 6mm male screwed into the radiator, and the 1/4" autobleeder (used on household radiators) screwed into the female end of this adaptor. You can turn the autobleeder open for manual bleeding, or set it where you like and it will bleed just the air/steam, and not fluid. You just leave it on your setting and anytime air gets trapped in the radiator, it will automatically bleed itself. It made bleeding the cooling system on that Pantera easy.
I realize you may have air trapped in the heads too and I've seen people install bleeders into the back of the heads.
(Sorry the picture is so small, it's the largest I could get it under 200kb.)
Michael
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