Did you change the valve springs? The carter 2bbl is barely 250 cfm Toss it and get the 4bbl of some kind without a stupid adapter. By the way the MSD can be a sourse of your problem I have had two that would slow the car down. Put a point dist in it and went 4-5 tenths faster. MSD are for race cars as far as I'm concerned too much heat from street driving and they act up
