[Mdman352]

I need help. I am working on a Comtemporary Classic Cobra that has been sitting in a garage for 15 years. The manifold and valve covers are filthy.

I already have tried:
Cleaning in a spray cabinet with 170 degree water.
Vinegar
Oven cleaner.
Liquid that is used to clean aluminum bodies on semis.
Although the valve cover is relatively clean, there is still some staining. I do not want these parts polished but it would be nice to have them CLEAN. My buddy says don't worry about it as the hood will be shut and the motor will be dirty in a few hours of running. Can anyone help with some suggestions. I am going to try and find someone with a bead blaster as I have heard that this process will work as long as it uses balls and not cut glass. Any help would be appreciated.
thank you.
David