a 6.0 is going to make a ton more torque and quite a bit more horsepower mod for mod compared to your 5.3. with heads and cam on an otherwise stock 6.0 block there's fbody guys making well over 400 at the tires with a decent cam(215/220 .534/.534) and good heads, so if you went with a slightly bigger cam you'd make a good bit more power. the 6.0 is basically an all bore 364 cubic inch 5.3 motor i guess you could say. it makes great power, this is why i'm going to use one in my ride till i can finish the big motor. what part of oklahoma are you from?