Governor Performance

We rebuilt my H engine, carb, and distributer and it ran smoothly at an idle but would surge non stop if it wasn't under load at higher rev. My brother is an engineer, mechanic and restorer of tractors of a differnt color. He's new to Farmalls, he inspected the govenor and couldn't see what was wrong with it. I had a rusty, dirty spare govenor I bought on Ebay for $9 he played with the spare govenor for a little while and said he can't find anything different between the two. So last night we swapped the shiney red govenor for the dirty rusty one. The tractor definately ran better, if it was at a low idle and I suddenly pulled it up to full throttle, it would rev up, surge about 3 times and even out. if I was driving and started up a steep incline the engine would barely start to bog and the govenor would adjust and it would rev right back up.
Is a sudden throttle up going to cause about 3 surging cycles before it evens out? Is the spare govenor doing exactly what it is supposed to do or is it still needing new parts, just not as badly as the original one? If the 3 cycles of surging is not normal I'm ready to start replacing parts, which ones should I start with?

I really appreciate the advice, sorry for so many posts and questions today.

You have carburetor "lean" "issues" that occur at the transfer between the "idle" and "load" circuits when the throttle butterfly opens.

open the 'loadscrew'a littrle till it smooths out