My International Harvester shares the same engine as your 650G. I found this information, and copied and pasted it. The confirmed remarks are not mine. I have used the chart to recently (less than 4 months ago) do the points and condenser, rotor and cap in my tractor. I will try to find my source so they can be credited. Try
Valley Power and
Sheaffer . And then please PLEASE
PLEASE tell us what you find and what works, or doesn't.
I have another list of cross references from stores other than NAPA, too, but I think they agree.
Ignition:
Spark Plugs: Champion (N4C) - NAPA 803C (confirmed works well)
Wires: NAPA 700172 (solid core) and 700168 (resistor core - needed if running a radio ect)(confirmed)
Custom short length sets are also available at Tractor Supply and you can length to suit.
Distributor Cap: NAPA EP710, Borg Warner# C 585 (NAPA part number confirmed)
Rotor Button: NAPA EP711 (confirmed (but you have to push back the metal tongue to get it on)
Points: NAPA CS360, Borg Warner# A 529 - new points set @ 18 thousanths
Condenser: NAPA EP300, Borg Warner# G 658