Ive used them all. All work really well.The BR is the TR calibration, KZ is the olds 442, and the CZ is the MCSS calibration. The KZ has the lowest shift points at WOT stock of around 4700-4900 rpm. The BR shifts a little later at WOT, and the CZ shifts the latest at around 5400-5600 at WOT. Part throttle driving is less active in the KZ, and BR. The CZ is more active on part throttle kickdowns. The BR comes with the largest servo stock. The KZ, and CZ have a smaller servo. All have various part throttle kickdown points. They all work equally well when a shift recalibration kit has been installed. They all have relatively low operating pressures stock and are rated for the engines they came behind stock. My favorite is the CZ for a cammed, headed TR. The later shifting and more active kickdowns is great for larger turbos and extended rpm automatic shifts. Keep in mind that they all need attention if used behind a modded TR. They are all equally failure prone otherwise. When built with billet parts, dual fed, and recalibrated for higher pressures with high performance clutches and steels they are equally strong and will survive many low 10 sec passes in a full weight TR. Thats just a quick summary.
