I have an unbalanced 235 with the M4F cam. It has turned 4,500 rpm, which is about 95 mph with my gear/tire combo. My friend has a hot 261. No comparing the engines, his is fully balanced, professional ported head, MSD-6 box, Unilite distributor, full race cam and dual 2 bbl carbs. He had the engine at 6,000 rpm doing burnouts.
It comes down to what you want to do. If I were doing mine again, it would be balanced. If you want to do it later, the price will be a full rebuild.
