Originally Posted by LasseNC
This is how far I got with grit 120. I might "water grinding paper", lost the word for it, and then call it a job done.
There are however some gouges in the fins, but polishing those up will simply be too much.
Looks good. You might have been thinking of "wet sanding"? Anyway, just blasted the heads on my rebuild may follow your approach, may leave it blasted.