I talked with Moss today. The guy I spoke with was very nice and also very helpful.
So, here’s the story:
Despite what I mentioned in my previous post, I had actually ordered p/n QR1178S. This was a single tie rod end (TRE) for a “6 cylinder 61-71 E-type”, for which I ordered two. This approach was cheaper than ordering the pair of TREs they offer under p/n C25447, by about 2.5X.
I received one TRE that was in a box that had the QR1178S number, and also the C25447 number. The other TRE was backordered. In talking with Moss, the QR1178S is a very old part, and has been superseded by C25447. As of now, if you search Moss for QR1178S it won’t even come up anymore. If you Google it, it could come up on the Moss website, but will be shown as “NA”. In other words, I don’t believe anyone else is at risk of ordering the TRE that won’t work, at least from Moss Motors.
The Moss rep was confident the newer, C25447 pair of TREs are the ones I need, and should articulate to the ~125° we 6-cylinder E-types need (reference the note that @davidxk mentions above). So, I ordered the pair of those, with free shipping, and was credited the original charge for the older part that wasn’t a proper fit. My fingers are crossed that the pair I’ve now ordered are correct - I will definitely measure when they are delivered!
RobY