[Michael Burbidge]

The directions say to use an AN4 bolts to mount the master and starter contactors to the firewall. One bolt, on each of the contactors is drilled through the 3/4 inch firewall stiffeners. That is a big bolt to drill through a 3/4 " stiffener. That cause edge distance problems? Did you use AN4 bolts for the contactors?

Thanks,
Michael-

 

[Mike S]

The main strength that the stiffener provides is from the other half of the angle stock.

The part you are drilling in mainly supports the other half----and there are a lot of rivets also to hold the part straight.

Drill on, and dont worry.