In a previous post, the solenoid pictured on the left is not GM, it is for a 68 up Ford unit. The others were used on earlier Ford, Chevy, Studebaker, Rambler, Willys, and others with a 1" shaft extension. The GM R10Q solenoid is somewhat different as it has a smaller center boss and a 1 1/2" shaft.
Fred

1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine