I bought a 84 D-50 about a year ago, 360 swap, 727, stock. Had a 2-barrel intake that I believe to be stock, engine seems to be rebuilt, sounds mean, never smokes, and seems to have more power but at full throttle it sounds good at first and eats the **** outa the tires then kinda falls on its face then sputters and pickes back up. The 2-barrel had a crack and I thought I found the problem so I got a edelbrock performer intake and a used rebuilt holley 750 electric choke carb and it still runs the same. It also sputters when at low speeds around 20 or so, so I think there must be a loose gorund or the distributor is cutting out. But thats why Im here is to see what some ideas are. Oh and it averages at only 5 miles a gallon. PLEASE HELP!!!!!!