While my 502 is apart, I am going to have the upper intake plenum and the valve covers stripped and powdercoated to match my graphics on my Sunny.

Would the intake plenum get hot enough to need a high temp powder? (more than 400 degrees) I can't think of a time I could not put my hand on it due to heat but I wanted to make sure before I wasted money.

Heat would not be a problem. Given the level of heat and possible fuel or oil contact with the pc surface, be sure to use a PC professional. IMHO, prep is 80%, 10% product and 10% application for great results.