I am currently working on a '71 Electra fittingly named "Black Betty" and was hoping for tips on fixing a hesitation at acceleration from a dead stop, and an easy way to upgrade the belts without changing the old pulleys. The hesitation was originally thought to be the carb, which is rebuilt now, then the distributor which is ow set correctly and the motor is running much more nicely. The plugs are new as are the wires and it's still hesitating off the line. Any thoughts?