Hydraulic clutch pedal question

DrCharles said
First part is correct. Second is not. Moving the push rod closer to the pedal decreases the ratio (nominally 6:1) which moves more fluid from the master for a given movement of the pedal! It also increases the effort required due to the same reduction in leverage.

I think you're calculating your pedal ratio from the original geometry, which has no meaning at all for a hydraulic clutch. No Z-bar, no clutch rod, and in most cases no clutch fork or pivot. The only thing that matters for the hydraulic clutch with regard to the pedal is the amount of travel for the push rod, and the location of the pushrod on the length of the pedal. The location of the push rod along the length of the pedal determines you mechanical advantage (totally separate from any hydraulic advantage present), and the distance the pedal travels from rest to stop at the push rod mounting location location determines the travel unless it's longer than the stroke on the master cylinder (which would not be good).

The problem is that when you're using the stock pedals you've already had most of the geometry laid out for you. The pedal height has been set. The length of the clutch pedal is set. The travel distance to the floor/firewall is set. You can move the push rod mounting location, but you have to watch the amount of travel, the amount of arc, and your mechanical advantage closely. And since moving that around also changes the mounting of the master cylinder, you have to make sure you can mount the master cylinder at that location on the firewall.

You're far better off making adjustments by changing the bore and stroke of the master cylinder. Personally I would move the push rod mount back up so that it's inline with the stock mounting point for the clutch rod and go from there (notice that on 72BBswingers set up there is no overcenter spring/clutch rod arm). I know that the 7/8" wilwood master cylinder works well with the T56 conversions using the Viper T56 slave cylinder, but I don't know what you've got in there with a TKO conversion. You may find that the master cylinder you have works fine with the relocated push rod, or you may need to change it in order to match the travel needed for the master cylinder up with the travel available from the pedal.