Lakewood No Hop bars help

[Zman1969]

I recently bought a used set of no hop bars(not the ones in pic) for my Chevelle and they were mostly complete except for the square plates that retain the bolt in the upper bushing mount does anyone have some that could give me the dimensions and thickness so I can make another set please? also I have never installed these before and I believe I have to drill a hole through the housing is that correct? Oh and if anyone has the instructions I'd be grateful TIA