I don't know about the Duplicolor engine paint, but the VHT engine color was marginal on the heat tolerance. The Yellow I used degraded at about 450 to 500, ( It was a nice color changer though going from bright Yellow to Amber with heat and back again before that) but that Rustoleum 2000 degree stuff is the best and hardest coating I have found. The flat colors look good under the 2000 degree clear, and Walmart had the stuff for around $5 a can. Clear, White, Aluminum, Red, Orange, Blue, Black, and VHT has 2000 Flameproof Yellow.