Tom,
Lets see if this might help. I Don't have a 70 Nova AIM so I will ask you to reference the pt# as these are from my Corvette AIMs. C head marking Bolt on left is pt# 3958062 recessed/flanged head with a notch in the tip. RBW Bolt on the right is pt# 9420825 recessed head tapered threads at the tip. Let me know if either # matches up with the Nova AIM.
I would have to see a picture of the head of the C bolt you have to see if it is a period correct supplier.
