just an example: My friend has an early 283 made into a 327. It is not dyno'd but works out to be about 400 hp. He can turn the motor up to 7500 rpm's with no problem. The reason I mention this is, this motor was just "thrown" together, nothing fancy, not even balanced! He's had it for years and still runs fine. To be honest, I'm surprised it still runs. That's why I like my chevy's, their tough little critters. Have fun.