put the pearl in the clear coat. I would clear coat the whole car with one or two coats, then mask for the flames and add the pearl to one or two coats of clear.
Put the first two coats of clear on the next day after laying the base coat. You can clear the same day but wait long enough for the base coat to flash.
Then when you mask for the flames you will have a slick clear coat to mask to and not have any tape residue left on the base coat. And if you have to wait a couple of days to paint the flames, you can scuff the original coats of clear for good adhesion.
You can't scuff metallic base coat.