I don't mean to hijack your thread but is the 630 the correct chain for the 77-78?
When I got my bike I ditched the seized '72 motor and custom rear wheel.
I picked up a 78 motor and have detailed it and I found a set of alloy rims off a '77 CB750A Hondamatic.
To my eye, the sprocket on the motor and the one on my alloy rims look like they have the same tooth spacing.
I haven't purchased a chain but knew I would eventually have to post this question.
Good info about the 88 links.
Johnny
Cypress, Texas