Exhaust mounting question CB750

[Automagic]

What year was it that Honda switched from exhaust stubs bolted on the head ,and clamps on the headpipes that squeeze  onto the stubs to seal , to the now more common split collars with  2 bolt removeable flanges?

[Re-run]

In 1977 on the cb750 is when they changed the system.

[Automagic]

That's what I thought. I just needed confirmation. Thank you!