I bet you can change the compressor. Only 3lbs sounds like there is something else amiss. I know its just a 1.6 but i have had 1.6 compressors pull very good power. remember the magnacharger 112 is 1.5 liters i think and have seen guys put hige power to the ground with nitrous of course aiding but still the 1.6 lysholm is a better unit hands down. Look elsewhere but 383 cubes eats alot of the air up. I bet you are seeing belt slippage somewhere. Did you get a new tensioner for the charger? experiment with bigger tensioners.