Yep, I am surprised too.

At the moment I’m waiting for a set of 9.400 pushrods to be delivered, as well as a pushrod length tool if these do not work. I have taken my pushrods out to measure them, they are the correct 9.315” size.

Like I mentioned this is a bit of a mystery motor, I think that maybe the valve stems ends were refurbished and trued up, making them shorter?