I would use a modern version of the six pack piston.....or the six pack pistons themselves. A lot of people will tell you they're heavy and they are in comparison, but at your power level, they'll be a good addition. Any piston that can get zero deck height is what you want. The heads will be fine, but if then need guide and seat work and new valves, you may want to look at aftermarket aluminum heads as the price to fix iron heads gets expensive quick.