My caster mod (with pictures)

[jnickell41]

So these will be going on a 1/2 ton '87 R10 so will have the rubber bushings.

The holes are 8.75 inches apart, 4.375 inches from the centerline of the shaft. I have included a picture of the box they came in.

I checked the shafts that came out of these lower control arms and they appear to be the exact same measurements, distance from the ends as well as distance from each other.

Am I missing something here, are the majority of the 1.5 inch measurements I've seen on this site from 72 and older trucks, or 3/4 ton trucks with steel bushings?

Any insight would be greatly appreciated.