Horsepower

If i took a 93 magnum 318 rebuilt it, put a carb on it how much horsepower do you guys think it would be also i heard you have to mill the input shaft or do somthin crazy to bolt it to an A-833 4 speed you guys got any ideas cheap things to do to these motors for horsepower or any neat tricks still not sure what i want to put in my valiant i got a 383 but its not worth the hassle with the clutch if it was an automatic car it would be done already Thanks