Hey..

I have an '83 Z28 with the glass hood, with some REALLY ratty hood insulation.

Can I just take the insulation off and run it like that, since I have the 'glass hood? I've heard that can do things to the paint on steel hoods, but have never seen it happen to any of the glass hoods (or steel for that matter) here.

 

Yes you can take it off w/no ill effects. Its main purpose is quieting underhood noises.
If you engine bay is getting hotter than a black cars hood in the sun on a 100° day, then you should start worrying.

 

Well, its a white car and the engine doesn't run hot at all... so all's good?

 

It's all good regardless. You don't need the inslulation. What he is trying to say above is that the temp of the paint gets way more heat from the sun than the engine could ever get it. My car has fairly dark paint, never had the insulation, and the paint is around 8 years old--look at the hood.