1977 750K compatible with 1981 cb750?

[JosephMN]

I own, proudly, a 1977 cb750k. I found a 1981 cb750 (not sure of the model) with a knocking engine for sale. I need exhaust and small parts for my 1977 bike and was wondering what insight could be given to me as to parts compatibility in this situation. I know my bike is a SOHC and the 1981 is a DOHC. I have included a picture of the 1981 bike in hopes that may help identify its model (i.e. F,C, etc.). Thanks in advance, this is my first post and hope to learn much here.

 

[dirtdigger]

Nothing is the same between the two, maybe couple of things could be made to fit but they are two different animals.