Firstly, yes I did the search and read previous threads. Still confused... Maybe I'm just stupid.
So I have an F engine #CB750E-2604689 that I was told was out of a '78 but I'm not sure. The piston is stamped 410 3 (I'll post a pic when I get home). I'm looking for stock rings and I thought the correct ones were 13011-410-601. As many other F owners out there know, Honda no longer makes these and no one seems to have any gathering dust on a shelf. I called totalseal and gave them the groove measurements (I got 1.2, 1.2 and 2.8 with my Lowe's cheapo digital caliper) they said they couldn't help me.
So I start looking around and see on several websites that the '77 F bikes start with engine # CB750E-2600004 and the '78 bikes start with CB750E-3100001. So maybe I have a '77 motor? Now I look on the motogrid website and see that rings with part # 13011-392-004 are to be used with engine #'s up to 2612797. Those are (I think) still available.
Can anyone confirm for me that those are correct for my motor #2604689? Something about using rings without the 410 in the part number seems wrong as I thought that indicated the model the part was intended to be used with.
