Tappet cover question

[OldStan]

I recently bought some tappet covers. At first I thought they were the same, then looking closer I could see they're different. The one on the right I believe is for the early Dreams. The thread sizes are the same, but the nut size on the left one is about 1mm smaller. Any help with identification would be appreciated.

[Tim Miller]

Correct the right one is what came on '61s and perhaps some '62s both CB72/77 and dreams.
The left one is what I was getting from Honda replacement parts in the 1990s but not sure if they ever came on any bikes.

Tim

I recently bought some tappet covers. At first I thought they were the same, then looking closer I could see they're different. The one on the right I believe is for the early Dreams. The thread sizes are the same, but the nut size on the left one is about 1mm smaller. Any help with identification would be appreciated.

[OldStan]

Thanks Tim. The left one was with 3 of the later style, so maybe it was a replacement also.