Another Vacuum Booster Question

I have been looking to add a vacuum booster to my 78 CJ-5. I know the CJ-7 of that year had available power brakes, but when I look that up, it's usually $100 w/ $150 - $200 core charge. But it will have mounting bolts 2" on center.

Ebay has conversion kits, but it looks like the bracket they add converts from 2" to 3 3/8 which it seem is what the rest of the world uses. And I'm sure it also changes the pedal ratio.

does anyone know what other make and model uses 2" on center mounting pattern for the brake booster?

Jay