[Oldsguy]

I usually use an engine de-greaser like Gunk, let it soak, and then start blasting away with a pressure washer. I suppose a steam cleaner would work well too. If a company is doing it, check about customer satisfaction and guarantees. The reason I say this is that they could make mistakes like blast off decals on the radiator upper support, oil fill tube or air cleaner. They may not plug openings like the oil fill, pcv opeinings on the valve convers, carburetor etc and you will end up with water in your oil or manifold . And they may not protect your distributor well and the engine won't start or start well after it is completed. I am always real careful when I clean my engines and check for all these things so just watch out for that.