The Ranger has a self adjusting slave so I don't think that has anything to do with the self adjusting pressure plate and the point at which the clutch disengages. I admit I don't know exactly how the self adjusting pressure plate works and the effects of it. However, I have heard an explanation from a source that seemed knowledgeable about it. It was explained that the self adjusting pressure plate deals mostly with the change in pedal force required to disengage as the clutch wears over time.
Whatever the function of the self adjusting pressure plate, installing one without this feature will work fine but you will have to deal with the minor issue the self adjusting pressure plate fixes.
2002 FX4 Bright Red Supercab 4.0 SOHC, manual 5-spd & Tcase, 33" BFG MTs, K&N air filter, Modified air box inlet, Gibson SS cat. back exhaust, Bama flash, Hidden Hitch round receiver, Rear helper air springs, Electric trailer brake controller, Line-X bed liner, WAAG bar with KC lights and Wildernest shell.