I have an 83 K5 with a 305 V8, 2.5 lift, and 33's, Edelbrock carb........ Here's the trouble......when I really hit the gas, it starts misfiring and sputtering. On the way to work this morning, I pulled out onto the highway and had to floor it to merge, and she totally died. She cranked right back up, but I almost got creamed. At slower speeds and with less throttle she runs great. I have checked the carb, and it doesn't seem to be running too rich or too lean, and I have checked all of the spark plug wires and they are all relatively new and are connected well. So, what do you guys think I should check next? New spark plugs?