904 question. Please help.

I would make sure you are using the correct dipstick or that its fully seated atleast so you know your getting a correct reading.

as for using the radiator to cool the tranny.......just something to think of in the future.....not sure about the older chrysler radiators but I know atleast in the 90's and up there was a check valve inside the radiator that was known for going bad and after doing so it would stop transmission fluid flow and would tost your tranny so I always bypass it all together and put an external cooler on