Goodyear bolt size

[KCOI7]

Hello, I'm about to change tires and would like to change the 3 bolts that hold the wheel half's together. Part#11 on Goodyear diagram)

I'd like to buy the bolts ahead of time.

Eyeballing the nuts, I'm thinking AN4. ( Uses 7/16 socket)

Can anyone confirm bolt specs?

Also curious how many Goodyear brake users have the spacers and the little spring? Part 9, first diagram 9521698 and part 12, second diagram, 9510151.