Hi all bought that trans am a couple months back been working on it a little. I'll start a thread on how all that's going but I have a quick question. Would rustoleum black spray paint survive a summer on the underneath side of the hood?

My hood has a hole for a shaker to be attached to the engine and stay there when the hoods raised. A rubber seal goes around shaker to seal the hole. Since I'm not using a factory quadrajet carb the shaker won't mount to the engine without spending $4-500 on a correct carb or $3-400 on an adapter. I don't want the shaker mounted on the engine anyway so I'm mounting it to the hood so when the hoods closed you can't tell the difference (unless you can notice the lack of actual shaking).

With that out of the way nows come time to install the shaker and the hood to cowl seal on the hood. In the near future I will install a insulation pad  under the hood as came factory (I think not sure yet). The underneath side of my hood is dirty/grimy and needs degreased and power washed. It's already got thin spots and oxidation on the surface and I'm sure washing it will uncover more. I don't want to leave this bare but I'm not gonna be ready to actually paint for another couple months if I even get to it this summer. I fear with the insulation in place even more moisture will get trapped on the under side surface of the hood.

Cars getting repainted black probably, would rustoleum do the trick here? Or should I go ahead and spray the underside with an actual auto body paint. Heat is really my main concern I know how spray paint can liquify or even burn if it gets hot enough and it seems like it's advisable to use the heat insulation to help protect even professionally sprayed paint. The car won't really be driven without the insulation but even with it the under hood temps must get pretty high since people have problems bubbling paint. I'm not going for show quality looks I'm wanting to put a hold on corrosion and protect the car. It would take me all Saturday to set up prep and spray real paint. Spray paint I could do on the car in 20 min or so.

Rustoleum takes forever to dry, but with proper surface prep it will stay put.

I would use Rustoleum professional (bigger silver can with black cap), Home Depot has it but sometimes it's buried on a bottom shelf.
It goes on thicker so you'll only have to do 1 coat.

I'd hit it with epoxy primer after I sanded it and cleaned it with wax and grease remover. It'll serve as a good base for your sealer and top coats.