Governor for MF50 Z-134 replacement

[MM in SC]

I am slowly aquiring the parts to totally rebuild my 1958 MF50 Hi-Arch with a Z-134 gas engine. I have removed everything from the transmission forward and am replacing every bushing, bearing, joint, etc. Even though I have not removed the timing cover to check it, I plan on just replacing the governor as the engine has never been overhauled. Looking at governors, the prices run from around $70 to around $135 for the same kit. That seems to be a wide spread for the same item. Is there one better than the other? After going through all this, I don't want to put in a poorly made part that will have to be replaced in a few years.
Thanks