Hi Bill, Correct, and also during oil change drain oil with bike off stand and lean to left [flywheel side] to remove as much of the old oil as possible. If the oil is drained on the stand with the front wheel on the ground, a fair amount of oil will not exit the drain hole.
It is easy to check the oil on the Ambassador, because of the side stand. Just loosen the dipstick, and tilt the bike to level, then check the oil.
All the motors use 8 oz. of oil. I have never seen a dipstick with 10 oz. marked on it before [sounds like a rare collectors item], all of mine are marked 8 oz. All the dipsticks I have in stock have an area ground flat and the number 8 has been stamped in, make me wonder if they said 10 and was ground out and stamped 8 [ I love a good mystery].
Have fun,
Quenton