With an aluminum block and aluminum heads you can get away with a LOT of compression on pump gas. The block will which away heat so quickly NONE of those ratios you listed would concern me as far as to much for the octane of the fuel goes. If it were me I would be shooting for the upper end of that scale if not higher. It is very difficult to build cylinder pressure in an aluminum block. Also if it were me I would look at a roller cam, solid preferable but hydraulic at least, they done have to be big to make power and not worry about lifter life.