Hi everyone, I'm new to the net, but not to the mustang. I 've had my Mach1 for 7 years. It's got an original 69' intake and autolite 4300 4v with a FMX 3-speed tranny. The problem is it surges when your trying to cruise at a steady speed. I had the Distributor rebuilt with an ignighter ignition and the 4300 is branny-new. I've played with the advance to no end. The only constant in all of this is the intake. Could this be the culprit? By the way the motor is the original 351w. I rebuilt it (with help). I had it bored alittle (0.30 over) with a step over stock cam. I'm thinking of selling the intake/4300 setup for an alluminum holley setup. Do you think this will solve the surge? Thanks for your help.