Under hood padding

The original flat hood on my 72 340 Duster does not have any mounting holes in it for the plastic retainers. I've never seen an original 340 car with the underhood insulation. I've only seen it on non-performance oriented cars with options like A/C, P/S and bench seat V8 cars. You know, cars with "creature comforts". The underhood insulation was not an option on any car that was equipped with cold air induction (any kind of functional hood scoop). All that said, if you want it on your car, why not add it.