Bolt sizes help needed

[Lippyp]

Can anyone tell me precisely what size bolts are needed to mount the power steering pump bracket (cast type) to the two holes on the front of a 69 350 sbc short water pump engine. I need size, thread, length and grade as I need to order them from a specialist engineering supplier.

You used a different set of standards in the US compared to us in the UK in the 1960's ( we used AF rather than UNC/UNF) and I can't just walk into any old hardware store over here and buy these bolts. I am replacing my power steering pump with the correct one rather than the bodged on later pump that was on the previously and the PO used shorter bolts to mount his home made brackets.

Thanks