Heat resistance is going to be a big deal, depending on where the item is that you're spraying. Block paint starts at 500 degrees, high heat is above that. If properly prepped, then sealed with a good engine clear coat, might work out. I would suggest taking an easy piece, small piece, like the cover over the throttle cables, and paint that first. Run it for a month and see if it stands up to it.
On my car I've painted the intake mani, airbox, etc. Used hi-heat block paint, with a cast aluminum finish. You can see in the pic below how different that is from SS look, as it's right next to my SS up-pipe. 8 coats of cast aluminum, 8 clear coats. I'm pissed now because I trimmed all in blue and that blue is fading, and that fade almost amplifies the fact that the clearcoat has started carmelizing. Pisses me off, was truly clear for about 6 weeks and is now geting this golden haze to it. Probably would have been fine without it, so if you guys use an engine clear coat, prepare for it to age quite rapidly from heat.
