Topic: What number on original Honda 4-4 exhausts 1976 500/550K2?

[Deltarider]

OK, I have only one source. In a test the German motormagazin 'Das Motorrad' (13-1976) mentions that Honda had increased the thickness of the exhausts from 0,8 to 1,0 mm. The problem is that in the picture we see both the 1976 built CB500K2 and the CB750K6. The test was a socalled doubletest.
Some 60.000 kms ago I have renewed my old original 4-4 exhausts on my 1976 built 500K2. I did a very good deal then, btw. http://forums.sohc4.net/index.php?topic=119831.msg1356926#msg1356926
Here's my question: I seem to remember that where now my exhausts have the number 323 on them, the original ones had a different number (could it have been 374?). I am just not sure. Now the same type exhausts were put on the 1976 550K2. Could any of you that has the original 4-4 exhausts on his 1976 CB500/550K2 have a look what number is on the mufflers?
I would like to know this for a reason. If new reproduced original exhausts are offered, what model are they a copy of: the old 0,8 mm thick ones or the later 1,0 mm ones? Or were they all the same and was it only the CB750K6 that went from 0,8 to 1,0 mm.

[FoxDK]

Hallo,

Here is a picture of one of my exhaust. I think they are original Honda? The number is: 323

As far as I'm told, had one of the previous owners a couple of years ago, installed these (new) exhausts for a lot of money 



Regards Frederik

[Deltarider]

Thanks. So yours have been replaced too. It's the same number that is on mine but... for some reason I seem to remember there was another number on the original set, that was on the bike when new. I await other reactions of owners who still have the original first set.

[Deltarider]

Anybody else? And what number was on the CB550K1 mufflers?