I have an auto trans(yeah I know I should get a manual but I live in soCal) 1992 Mustang GT. I know 3.73 gears will help but what about any engine upgrades. I have a CAI, alum radiator, MSD distributor cap.
How many miles are on it or the current motor at least? When was the last time you did an actual tune-up. Plugs, wires, an OEM cap and rotor, fuel filter, etc.? *If* the car is mostly stock then there was no need to go with MSD anything on your car. They make great ignition boxes, but the distributors and cap/rotors suck. I've built a lot of really fast street motors and always run the stock distributors. CAI is just for looks. They do no justice for the money one spends on those kits. Should have just left the stock intake tract on unless you like showing off under the hood at car shows. Have you sprayed out the mass air sensor? They make a cleaner specifically for them if in case you didn't know. Run Seafoam through the intake system by sucking it in from a cup through the vacuum hose at the brake booster and shut it off for about 10 minutes to blow the carbon out of it when you start it back up. Repeat if carbon buildup is heavy. Use half a can each run. CRC makes an electrical contact cleaner, too. Unplug anything you can get your hands on and spray out every connector. That helps, too.