[Daves55Sedan]

The '56 Ford-o-matic shop manual says 5 quarts. But I found another source that says 19 pints. That is equivalent to about 4-3/4 quarts, right? Use Mercon fluid).
I am more comfortable with 4-3/4 quarts, since this raises the level of fluid right at the center between the marks on the dipstick. Keeping the fluid level here, I have never had any fluid blowing out or blowing seals and the transmission operates properly.
Check fluid level by running engine at idle with gear select level in neutral and fill to in-between the markings on the dipstick.
If you have completely drained fluid and are filling it from dry, idle the engine with foot on the brake and run through all gears first P-R-N-D-L, then shift back into neutral to check fluid level at the dipstick.