I've been reading up on rebuilding the 454 that came with the k5 when I bought it. I looked up the casting number and it shows that it came from a corvette and with a hp of 270. Now I'm fairly new to working with engines so I'm seeking some advice. I looked up some newer 454 crate motors and they show around 425horsepower and 500 lbs of torque. Can I get those kind of numbers from my block without superchargin it or using nitrous?