In march of 1994, mustang monthly printed a article on how to detail a 428 cj engine, by perkins restoration. On the first page they listed ditzler dar 13358, dxr80 urethane hardener, and dx 265 flatting base @ 25% to 30%. At the time I couldn't believe that you could use body paint on a motor and then drive a car hundreds of miles to a show and the paint hold up. So, I called Bob and told him that I was in concours driven and drove long distances to shows, and how could this paint hold up? Bob said that the paint with the hardener would hold up to being driven and it didn't matter if I primered the engine or not as long as the metal was properly prepared. In the winter of 94 I pulled my 66 mustang engine and stripped it of the krylon spray can paint that wasn't holding up to well. I primed the engine and painted it just like bob told me to. I now have around 20,000 miles on this engine paint and it still looks as good as it initially did. No peeling, no cracking, or bubbling either. When I restored my 68 in 1999, I used the same system on the engine except I sprayed blue straight to the metal(no primer). This engine now has about 9,000 miles on it and looks great as well. I would highly recommend the ditzler product. It is worth the extra price and effort for the look and long lasting finish. If you prepare properly this will last years like it has me. Bill.