i haven't heard back from Inline Tubes. I did go to AutoZone where i had ordered two hoses. the first hose was a front drum hose that had the correct thread count (24), but the fitting was different. not that it couldn't have worked, but compared to the other part that i ordered (77184Z), which is the all in one unit (Standard for 73 & 74), i opted to go with the all-in-one.
i figure it is one less connection point to be a potential cause for a leak. other than not having a hex shape at the connection point, it looks pretty close to the two-piece set up.
i still would like to know why there were two different thread set-ups. if anyone knows, that would be helpful.