86 GMC Power Steering bolt missing. What size is it?

[BladeX]

In the picture....
Power Steering Pump.

The right bracket is show. Or Driver side. Cant See the Screw i need. lol But its suspose to have one over there.

Im missing the bolt on the passengers side bracket.

Anyone know the thread count? Size of the bolt .

Im so clueless to where it went.

But there are 3 bolts holding it on. Right side bracket is attacked to the bolt thats on the manifold. Top one is connected to the block and the passengers side has a bracket with a screw that im missing.

Any help is apperciated. Thanx.