Could anyone out there let me know if there is a engine paint that will will not dis-color from heat? I tried the 500 deg. duplicolor engine enamel (With Ceramic-? ), after about 2 min. of run time the heads are dis-coloring. I realize the head temps. are high, but what kind of paint are you guys using, and how well does it hold up to the heat? (Prefer Original Metallic Pontiac Blue)