I decided that the engine needed to be painted. I decided that I could not easily get all the surface rust off using wire brush or scraping or chemical cleaning. I got a portable sandblaster and a bag of "black diamond" blasting media from Tractor Supply. I taped off everything that I did not want to get blasting grit into. I then put on a clear faceshield and covered myself and the engine with an old bedsheet to contain the blasting spray. Holding a flourescent worklight in one hand and the blasting gun in the other, I blasted all the non-aluminum surfaces on the engine. These LSx iron block engines do not have much exposed iron. Front, rear, and valley covers are aluminum and the heads and oil pan are aluminum. Used about 60# of the 80# bag of "black diamond" and took about 1.5 hours to finish blasting. I will spend the next year cleaning black specs from stuff in my garage, even trying to contain it with the sheet. I then painted it with spray can self etching primer and then spray can krylon engine paint, cast iron grey color. It turned out exactly how I wanted it, a dark grey that has a bit of a gloss to it.