Topic: CB750/4 case halves question

[Boomologist]

Hi,
First post here and hope someone can help.
Recently I was given a lot of CB750/4 engine parts. They're all in boxes and cases have been split. I can identify the upper case halves by serial number but can't find any identification for the lower case halves. Were the lowers the same for all years?
Thanks in advance,
Ron

[ekpent]

 It will be said soon that the upper and lower cases are a matched set and should not be swapped. Chances are that yours are probably original to each other if someone just tore it apart.  Does it look like more then one engine worth of parts in the boxes ?
  Welcome to the forum !

[bryanj]

Yup, machined as pairs and can not be mixed

[754]

How many case sets are we talking?
 Slight differences on some years. But as a rule can't be mixed.
 You should be able to mate them back up by color or cleanliness of parts, maybe dowels .
 Tell us the serial numbers, we can tell the years.  There is a difference in bearing width of output shaft in 73 and again in 77.
 I can help with the year's of the top ends if you have a clear pic of the top front fin on the head, and sometimes there are numbers on top fin on back of head in the middle.