[madmaxx]

FWIW an engine which does not run or is not reliable or as important cannot be trusted is no fun. I like Kirkham reply, keep it under 5.5K rpm's, if you need more power then go more cubic inches. Valve train is the weakspot. The lighter the spring pressures, ie milder the cam, the better the reliability. Speed kills not only people but also engines. I would much rather have 600 ft-lb of torque and 400 hp than 600 hp and 400 ft-lbs of torque. 99.99% I am driving WELL under 100 mph, torque is fun.