lost all tranny fluid at once,
There's a transmission fluid cooler incorporated into the radiator. If it's rotted out you can get coolant in the transmission fluid and/or transmission fluid in the coolant. You'll have to flush out the transmission, which can open up a new can of worms on a 44 year old tranny, flush out the cooling system, then replace the radiator and anything else that's sprung a leak after you've flushed out the cooling system. HTH. -Jim
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