Had to mill the 10.5 TRW's down to flat because it pinged at full advance the last time the Government "helped" us with low octane fuel. Heads are milled to NHRA min, .040 as I remember. Felpro .040 head gaskets. Still need to run premium, 92/93. It is a street driven car. There are many combinations that work. I don't think I would try 2.02 valves on a 273. Not worth the risks and hassle for me. I'll look up chamber size tonight.
