Antenna mast, hood liner questions

[chrimsun]

Does anyone know if a retractable antenna mast has to be specific to a particular brand/model of power antenna controller? I have a hirschmann power antenna but the mast is broken. Can't seem to find one specific to the particular controller model. Would another model's mast from the same period work?

Also, how much space does there need to be between the hood and engine and engine related components for ventilation, if any? I was considering doing a hood modification with some polyiso foam. I was going to put some 1/2 foam core on the bare underside of the hood and then glue the new hood liner to that. Would the extra 1/2 inch or so provide too little clearance?

Thanks for any ideas.