Based on some research I think my clutch throw-out bearing (perhaps wrong phrase) is going out.
When I first press on the clutch pedal it hangs/pops noticeably. This seems to be getting worse. I have lubricated all of the friction points to see if that made a difference but it didn't.
Does my assessment seem correct?

 

Sounds like the throw out is hanging up on the transmission bearing retainer(the nose of the transmission). Or at least something along those lines.


Not exactly like yours(just borrowed from the internet), but just giving you an idea of what it looks like inside the bellhousing. The bearing rides on that tube(bearing retainer) and if there is issues between the surfaces it could hang up. This picture shows a crossbar to operate the bearing, unlike yours which has a pivot arm from one side.

 

2 X Freightrain. The throw out bearing sliding back and forth on it so many times wears a groove in to it. Eventually the T/O bearing tries to rock and grab in to that groove rather than sliding smoothly. This input shaft bearing retainer bolts to the front of the tranny. To replace it you'll need the bearing retainer,gasket,and input shaft seal. And if yours is a NP435 there is also a bearing race pressed in the back side of it. In the below pic the bearing retainer Freightrain and I are talking about is the tube/cover assy around the input shaft of this tranny.

 

Make sure your engine mounts are in good shape, and the z-bar hasn't lost it's nylon bushings. Since this goes between the bellhousing and frame, if a mount is collapsed it will put extra strain on it, and I have had them split and spit out the nylon bushing as well.

 

Ok, I know it is heresy to some of you guys, but I let a local auto repair shop take a look at my clutch. I kind of needed this truck back on the road pretty quick as it is my daily driver and my mustang was sitting at the dealership and my 71 has no insurance.
He installed a clutch "kit" and replaced the flywheel. They said they were able to adjust the clutch to the point it was working right, but said it was pretty worn. After they dropped the tranny, they then found some teeth on the flywheel were chewed up pretty bad. When I first bought the truck, I had to replace the starter at the PO's property (hand him the money and the starter goes out, sort of). Well when I pulled the starter, there was a washer stuck in the fly wheel teeth.
Asked the mechanic if he thought the clutch being out after only 33K was an indication this truck was no so low miles after all. He said I had no idea how the previous owners drove it or if they tried to tow with that little six and that light duty tranny and rear end combo they would have worn it out much earlier than it should. Plus, it apparently set for a long period.
The truck does have air adjustable shocks, indicating it was used for some towing.
I will say, it is much more enjoyable to drive. The difference in clutch operation is much different - releases a lot earlier, no noise, smooth. I am picking up one very slight little rattle/whir/not sure how to describe sound when I initially step on the clutch when it is in gear. Will see if that develops, or if am just hearing things.