Lol! Could very well be. I actually had both in the bilge with me, and the 22mm was the one that fit. Purposely used a combination wrench instead of a socket so that I would get the better feel for it. It would be a home run if the head was 7/8” and threads were 1/2” like Frank’s. Should have taken a time out when the drain plugs were out and taken a ride to the hardware store to verify the thread size. I’d really hate to cross thread the transmission cases.