Measurements from our clutch builder back in the 1970's-80's using brand new cylinders ????? I'd be curious if either (1) you are using different cylinders than we measured back in the day, or (2) if stock cylinders have been changed/improved ???
1. Like written above, the LUK's do work, but rely on the entire hydraulic system being in perfect condition to achieve max bearing travel.
2. I've been out of the business for too long now, gave away all my Landcruiser data, but I do know Toyota had 3 different slave cylinders, and each had to...
^^^^^bikersmurf got away with the LUK because it only takes .400" of travel to disengage, and the Toyota hydraulics produces .420" of travel (at the bearing). Problem with the LUK is you are out at the ragged edge should the hydraulics have any wear/leakage/damage/loss of travel, sooooo congrats...
Stock Chevy clutch requires .500" of travel (at the bearing) to disengage, the stock Toyota hydraulics only produces .420" of travel, that's why Downey makes a Chevota specific clutch that only takes .375" of travel to disengage- - -just saying.