Got my engine out. Sprayed oven cleaner but it left a lot of gunk on the engine. What is the best stuff to get 40 years of gunk off?

 

Dismantle everything and take it to a machine shop for a bath lol! Non-clorinated brakleen works well but it's expensive and cans last about 60 sec at full spray.

If you don't mind scrubbing Goo-Gone Xtreme is great with a wire brush...just time consuming.