Rear brake shoe retainer

[jimpainter]

Does anybody know the thread pitch and length of the bolts that hold the brake shoe retainer onto the backplate/hub. There are 2 together at the bottom of the backplate that go through the retainer and into the hub. I have to replace one but dont have the time to remove the drum etc before getting the bolt. Its an asap job that i need to get the bits for before the van arrives.
thanks