Hello I am thinking about starting my big block project and am looking for some info on a factory block and an aftermarket block. First off this is strictly a street motor but has to survive the dyno. Secondly the motor will be low compression with a 8-71. What I am really curious about is trying to keep the motor cool while cruising around town. So my question is would an aftermarket block have better cooling being thicker cylinder walls and better flowing water jackets. Would a person notice a difference?? And if I decide to go with a stock 454 how high of hp can I person safely go?