[TAGibb]

Is there a good way to paint inside the cowl on a 1970 Challenger?

I do not think I can spray into all the hidden areas? Maybe brush the hard to reach areas?

[dave-r]

I think you have probably answered your own question.

Also if you put enough in it should run down into the tight bits. But it will also leak out into the engine bay a little so watch out for that.

Personally I wouldn't depend on paint only for rust protection in there and didn't on mine.
I just removed as much surface rust as possible, sprayed/brushed a rust converter in there to eat the rust and turn it into an inert hard finish, and then sprayed in a heavy layer of black paint and then a heavy layer of cavity wax to seal it all and keep it from ever going rusty again.

The top of the cowl I painted black too as many of the lighter colour R/Ts were.

[Alaskan_TA]

I used a sponge. Dip in paint, squeeze out excess & go for it.

Long, bony arms help.

Extremely messy, so try to do it before shooting the body.

[TAGibb]

Sounds like a good plan I picked up some foam brushes today. Should I do it in body color? with or without a clearcoat?