390's? I ran two 660's on a stock stroke 340.Good response, very streetable but the 660 accelerator pump setup was HARD on fuel. I had 4:30's and a 3500 stall-nothing crazy. I think the secret is buying GOOD carbs, the RIGHT carbs, and a little tuning knowledge. Thats it. Really. Most that dont like rams usually blow it in one of these areas.