Originally Posted by ROLLGUY

After Blue picked up the engine in Nor.Cal., he drove down to San Diego to a place (the only one on the West coast) that does dry ice blasting. This process cleans without leaving any residue of any kind, and does not harm paint. You could even clean electronics and circuit boards without harming them. Blue even took the valve cover off and had the guy blast the cam and everything else under the cover. This is an amazing process.
Photo of engine after cleaning: