swapping primary gears xb12 to xb9

[LifesHarlequin]

Interested in this myself

This may be a dumb question, but I've always wondered. Has anyone ever gone the other direction and put an 12 primary in a 9? I've assumed this would lower the RPMs on the expressway when going 80 but would obviously hurt any low grunt that the 9 has. Again, I've always wondered so I thought I'd take this opportunity to throw it out there.

With 1000cc Japanese sport bike levels of torque from the XB9, and lots of high way cruising for my daily commute, plus the supremely careful throttle control required for around the parking lot, I"m surprised I only hear of people going from the XB12 to 9 gearing and not the other way around. I average 45mpg being a hooligan on my 07 XB9SX, but would love if this thing had more top end. I have a deployment coming up and when I get back I'd love to throw a hotter cam and a shorter gear ratio at the XB9 to bring top end power into its life.

I'm assuming it would be as simple as the normal 12 to 9 swap, but in reverse?