I use Magnet Paints chassis saver and with scuffing paint sticks great even after it dries or you can top coat it within an hour, but never tried it. My experiences with por-15 have been poor at best.

68 Road Runner, 69 Belvedere, 71 Challenger Vert
340 barracuda, 01 Ram CTD, 95 Ram, 04 Ram, 85 Daytona turbo Z
66 GTO, 06 Magnum RT AWD. 07 Ram CTD, 07 Ram