Your fine with the 405's but if you haven't bought the pistons, I would go with the h116p's get it closer to 9.5cr. 308's are nice, Check between the valve seats to ensure there not cracked though, most are. Throw the rotators in the trash. Go with regular spring retainers. 320-350hp with your above mentions is attainable.
I looked these pistons up. Thank you, I think this is a better fit for sure. So at 9.5:1 and a mild cam, is 89 octane do-able? Really trying to keep him from having to run 91 or 93, just because of daily cost for him.