SM Head Modifications on a budget

I think in the 270s are possible, especially if we start relieving the chamber a little.

I can tell you that with an RPM head, 270’s are possible without the 2.05 valve or any chamber mods.
Pinch at .970 and some pretty “safe” bolt bulge shaping.
But……..it did get some worthwhile SSR work.

Made 550+hp on a 416.