I have an 83 malibu with the same problem you are having, it had the original quadrajet on it, and it had no power, it would backfire, misfire, all kinds of problems. I changed it out for an edelbrock 500 cfm with mechanical secondaries, instead of the vacuum secondaries, I jetted it up, put smaller metering rods (for more fuel flow). and It will burn out so incredibly now. If you floor it, it will burn out for about half a second before it shifts into second gear, but it keeps burning out, I have pegged my speedometer at 85mph while sitting still burning out!!!!! My 350 is really hot!