Well, here are two very long shot ideas, Deegs: 1. you haven't mentioned a hydraulic clutch but if you have one, cold fluid or a cold slave cylinder can cause some delay in releasing the throwout bearing until the fluid/cylinder gets warm (if that is happening, the spring returns the pedal to its normal spot so you might not see any difference). 2. If your clutch pedal is hanging up on the floor sheet metal (the hole through which it passes or the leather/jute pad that seals the rod), I suppose that is a possibility but you would see the pedal sitting lower than normal and I don't know that warming up would change much. Maybe it could expand the hole's diameter but as I said...a long shot.

It sounds like all inside the clutch should be okay.

The only time I have seen an all newly done clutch slip was when the pressure plate was faulty. It did not sit parallel to the flywheel. Three of the 8 rivets holding it did not get correctly attached to the spring assembly (two failed to get attached at all and one was just barely attached) so as a result one side of the plate sat closer to the flywheel. I would eliminate that possibility because warming up had no effect and it slipped all the time.

~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end