The Grey card is used at the shooting stage shoot a few frames (use single frame capabilities of your Super8 cam) at different exposures (f/T stop) with a grey card to see how correct or far off your dev. times are. One frame or a series of frames if you don't have single frame capabilites should be shot at the metered exposure and from there you increase and decrease the exposure (change of f/T-stop) in 1/2 stops. Clip tests means a small amount (a clipping) of the film is used for test purposes. You should also put a reference to the base exposure time and difference between metered and changed exposure time in the frame (again at the shooting stage). Say a small piece of paper on which you write metered exposure, on the next paper if you increase the exposure e.g. +1/2 Stops etc...
For neg development the baths are the same for reversal processing look up the steps on Kodak film data sheet for 7266. The time for X-tol is probably close to that from D76.