'69 Nova Firewall Paint

[SeattleCarGuy]

Hi guys,
I had my subframe, radiator support and inner fenders (front wheel wells) powdercoated in a 60% gloss black powdercoat. I usually paint my firewall, outer heater box and underside of the car in a semi-flat black, which is a bit duller than the 60% gloss. Anyway, I called the company that supplies the powdercoat to the shop I used and asked for a paint that matches the 60% black of their powdercoat. I got it and sprayed the firewall, but it really looks too glossy compared to what I am used to seeing when I use the semi-flat. Also, I got a bit more orange peel in the paint than I would have liked so I will probably sand it down and respray anyway.

What do you guys typically use for the correct paint on the firewall and underbody for a '69 Nova, Camaro, Chevelle?

Thanks,

Paul