If that motor is dirty, then mine has been kicked around in the pig pen. My first thought when I saw yours out of the car was that is it was immaculate. I'd post a picture of mine here, but I don't want the embarrassment. Cleaner? Start with something mild like Simple Green. Move up from there to carb or brake cleaner
I have had lots of luck with Simple Green, then Carb Cleaner, then Brake Cleaner. Lots of elbow grease, and clean towels. WD40 also works in many places. Your valve covers do not look too bad. Some detergent water and brush work there too. Then again, if you can't see it when it is all installed, don't spend too much time polishing a cannon ball. I am guilty of that too.
I am sooooo tempted to do this. I'm eyeballing a MaxJax for the lift. Please keep the updates coming.
I can say brake cleaner will attack any silicone sealant, like between your oil pan, and the rear main seal cover and on the transmission covers it will melt it out of the seams. So if your resealing everything no problem, If you don't want to tear it all the way down well be careful with the brake cleaner. I love the stuff but its probably going to give me cancer
+1. Brake cleaner is nasty stuff...in a good way if used correctly. Simple Green, engine cleaner, degreasers, etc are your best place to start. Even those can cause discoloration on some parts.