I was reading the TSBs today (slow day) and saw the "dipstick length" article. Says that proper dipstick length is 38" and that early cars had TOO LONG of a dipstick. So having nothing better to do, I pull my dip stick. Original motor to the car, early 71 s/n 1744. Know the dipstick like the rest of the motor came with the car. Dip stick is a short model that just sticks up above the valve cover edge next to the firewall. Measures 21" from base of handle to tip. Handle is Ford blue, not yellow. So WTF I guess so much on that TSB.
Second, using that dip stick, when I put 5 qts of oil in the motor, it reads exactly full. So I have never thought about the dipstick being wrong. Look in the blue owners manual and it says 5.5 qts is the capacity of the motor. Reading here, there are comments about "add another quart" as it's "safer for the motor". Reading EVERYthing I could find on the web from the mustang community it is pretty clear the stock pan is a 5 quart pan and to run 5 quarts, NOT 6.
So curious on your thoughts to both.
p.s. dipstick stock no. is DOAE-6750-A. FORD with a "K" stamp