Hot rod black or not...

OK, here's my .02 - take the money you'd put into your Dart to paint it black and start your 'finished paint' account. You'll be that much closer to your finished paint.
I just don't see the point in doing something twice.
Also, as long as you're doing your own bodywork why not eliminate both the round '68 marker lights on the front fenders and the '69 reflectors on the rear quarters? Smoother look.