My truck is an 81 C10 1/2 ton SWB that HAD a 305 V8 but the previous owner put a 350 V8 in it. I just want to know how much horsepower it has. I'm trying to hit 300, by installing a new camshaft, but I want to put in a Low RPM high torque, so as not to lose much gas mileage. Anyone know? Thanks!