Ok I put everything together and it seems I have no clutch release at all. I'll go though and double check the clutch adjustment but at the moment it's not looking good...

Just play with the adjustment on the fire wall, and you should get a pedal...

If I fully back off the adjustment at the firewall the clutch pedal goes to the floor and seems have no effect - ie Can't shift with motor running and it feels softer than it should.

If I fully tighten up the adjusting nut the clutch pedal has very little movement but still seems to have no effect. what movement there is feels soft.

Can anyone tell me what the symptoms are of a thrust bearing carrier too long, and a thrust bearing carrier too short?

Fully tight and fully slack aren't what you want you want to have the adjustment so that the clutch engages and disengages porperly, have you tried any other adjustment in between? Or just tight and slack.

Yes I tried all in between, I was just stating the extreme cases. The only effect I observe of adjusting the nut at the firewall is the amount of pedal travel.

It is currently adjusted to the spec in the manuals (to the best of my ability). The clutch still seems to have no effect and has about a medium amount of travel.

Maybe it's the gearbox, but it would seem unusual not to be able to shift into any gear. I can just shift into 5th and reverse but it doesnt sound great when I do.

I'm a bit confused as well.

Did you use the sandwich plate or engine plate that goes between the engine and gearbox? I had a similar issue but the adjustment sorted that all out.

I have a plate like this one:

can you try the other carrier, sounds like its not engaing as it should. Is the 5 speed clutch cable operated too. nice score if so.

Yeah it's cable actuated.

If the pedal stops before going to the floor, does that mean the thrust bearing is pressing up on the clutch cover(?) Wouldn't that then mean the thrust bearing carrier is adequate?

Or perhaps the release lever is maxing out it's travel?

What fork are you using? this is the part that comes out of the bellhousing and conects to the clutch cable....its the four speed one you should be using, compare it to the 5 speed one, see if its differant...