A little old but thought I should leave a comment. When i replaced my engine with a gm long block, the instructions made it very clear to make sure the intake was clean before installing it on the new engine.
I prepared myself with a few cans of cleaner but before starting, thought i would consult with a friend of mine who owns a shop. They do many engine replacements. Asked about the intake cleaning and he told me to not spray anything in the intake. Said it was very difficult to remove liquids from inside the manifold. Just a note. If ya plan on cleaning intake, use something that evaporates (which is probably what was used here so not applicable) Anyhow, if ya feeling froggy and decide to use, lets say soap and water, plan on an extended drying time as shop air, shaking, cussing, might not get all the liquids from the runners.