somebody maybe should have run spring shims between the bottom of the v. springs and the head. it kinda looks like someone cut the guide bosses down for triple springs and/or guide seals.
I've never seen another aluminum sl/6 head. It would be cool if someone could digitize the surface, so someone could recreate all of it except for the water jackets.
I have a CI sl/6 head that has "SPECIAL" cast into it. IIRC, I put 318 valves in it, & hogged the bowls out. I can't remember where it came from, it might have come with an aluminum sl/6 block I bought several decades ago.
