[RICK LAKE]

Cobra3170 First off, Bruce the car is just an animal. Gear change IMO will not help. Go lower and load the drivetrain, Makes the motor work harder and not be in the power band of torque. When the motor gets into the torque range, the tires are smoked. Higher gear range the problem will be worse. Hit the throttle and smoke the tires quicker.
Have we looked into changing the ratio of the throttle linkage to slow it down? Some of the input will be the driver changing his style of throttle control. I am not in favor of traction control but Fred K from New Hamp has a setup that takes out timing when the ecu see slipping different between driveshaft outout and reartire speed change. He uses a FAST system. He might have a couple of ideas on this.
killing air flow with spacers or covers that limit air intake will cause reworking the fuel tables and timing. I don't think the motor will be happy at all. It's power design was for middle to large tracks. Top end on this car about 180mph. Having it run in a bull ring, just doesn't work. The other problem is THEY DON'T want you at these events. The car is stock body and frame with work from the 60's. You are kicking a$$ at each event unless the car break or driver error. They will change the track design to slow down the speed. This is not just you. I am guessing they are looking at safety also and want to keep the speed down incase of a car loosing control and hitting something not on the course.
Bottom line is too much motor. Detune it about 150hp. Your times will not change that much and maybe going to a 3.54 ratio will improve the accell and decell without blowing the tires or lockup. Using a higher rpm range might improve your time and handling also. Your driver is smooth and carefull from watching the videos. This makes the car fast.
Each event you run has a different surface. If you have the right tires to match great hookup and traction, great. IF not even your driver can over come a traction issue. It's like nascar, you will change shocks, springs, roll rate, stablizer bars and load, tires, and alignment. I am sure you have done it but are the tire temps about the same after a run or not enough heat buildup for good readings? I know you will not do this but good old down force of wings, spoilers and canards.
You have a great car that on any normal track can cover 98% of the field. Auto cross is a silly class of racing. Fun, low speed, Maybe 1 gear change, and power sliding a car. Running with the best and trying to beat them is what drives you. I guess keep beating on the drum and have them worry. You will change the suspension and come back with a better handling car, different tires, maybe a little less HP and scary the hell out of them again. Now that's fun. Private garage against the world, my favorite fight. Rick L.