David, first give the part a good shot of brake cleaner to get the dust from the bead blasting off. I would then shoot with some acid etch primer. Next I would use some 3M Bondo, and follow up with their red glazing pinhole putty. Hit any bare medal spots (from sanding) again with the acid etch primer. If it still is not perfectly smooth, I would then spray a layer of sandable filler primer and sand again. Start off with a 400 grit and go up to 800, then topcoat.
It should look better than the factory finish.
Only bad thing is that you complete all of these steps, its probably going to look better than the rest of the engine!