I have a 66 GTO with a 2 speed auto trans. Assuming it was a powerglide, I bought a shift kit and tried to install. Found out it is a ST-300 (super turbine) instead of a powerglide. I have been unable to find a company that makes a shift kit for that trans. I wanted to keep the same trans but get rid of some of the slippage and pep it up a little. Any ideas of what to do.
