What's the difference between the IP's that came on school bus engines, and the IP's on a pickup?

I have the old IP off my "new" engine that came out of a school bus and I just wondered what the difference between the two are.

 

i think they are governed to rev lower.
but im not certain.if you search here,im sure you'll find the answer.
i read this way back along,so don't take my word for it.

 

I recently asked the same question of a pump re builder and he told me the only difference is the throttle linkage

 

The cold idle solenoid and throttle linkage are different for sure. The throttle linkage won't allow the cruise control cable to connect to the throttle cable. The cold idle soleniod seta up alot higher. If you try to use the cold idle solenoid with a throttle linkage from a regular truck, the throttle linkage won't even come close to touching the cold idle solenoid.

 

The industrial IDI pumps are governed at 2800RPM and cold idle is 1200RPM.

Pick up truck IDI is governed at 3300RPM and cold idle is 800RPM.

 

Not going to bet money on this, but i was thinking the engines used by IH were governed at 3k and the ford used ones were 3300. I had no idea about the external differences.