It's called VHT Case paint, most good auto parts stores sell it and it is about as good as you will get. For best results you should allow to dry and low bake at 100 C as per the instructions on the can. One can will do an engine and have some to spare, I use the same stuff on hubs. This stuff is designed to withstand oil and fuel as well as high temp. Around $20.00 a can.
