Help!!!
I have a 69 427 which runs really strong. It is numbers matching except for GM aluminium heads, intake, 4bbl douple pumper, and a huge aluminium radiator. I am running a centreforceII clutch. All of this is as it was when purchased from San Diego last year.
A couple of months ago I had it on the Dyno and blew the cluster gears, VERY sad day... Took the car to the most reputable vette shop in town who rebuilt the box (M21) at exorbitant cost and at the same time replaced the Throw out bearing (which was shot) and the fork - the spring steel on the fork had broken off one side.
Got car back after remortgaging house to pay bill and all was well. Perhaps 200Miles later a noise started coming from the clutch area which could best described as a mettalic rubbing while the clutch was being depressed (changed frequency with engine revs) and trouble changing into gears. Problem was worse hot than cold.
Took it back to the man, who siad that because of the centreforce clutch the geometry was all wrong and I probably wasnt getting enough travel. - this didnt explain the noise, but I didnt think of that at the time.
I have modified the geometry slightly by drilling a new hole in the top Z-Bar arm, closer to the pivot point, giving slightly more fork travel for the same pedal travel. Although this allowed me to fully disengage the clutch, it didnt address the noise issue.
I put a hundred miles on the car last saturday, and by the time I got home, I was back to having trouble disengaging the clutch and the noise had changed a little.
Last night I dropped the box out myself, so that I could see the problem. As I pulled the box, the throw out bearing dropped out. When I got to the fork, I found it was mashed. See photo in my gallery (how do I put them here?)
I was sure that the original throw out bearing was bigger than the one in it now...
My Questions are:
Has anyone experienced similar problems?
Are there different types of throw out bearings?

 

I can see no pictures or a gallery for you.
yes there are two types of throwout bearings a long and short one. I believe you should have a short one.
Make sure the T/O bearing is placed into the fork correctly both the spring and the tines of the fork should be in the groove of the T/O bearing. I've seen many instances where the tines of the fork were over the top of the bearing with the spring in the grooved area ,That is wrong.
Redrilling the upper hole of your cross shaft for the pedal throw WILL NOT change the geometry of how the lower rod & fork disengage the clutch/
my .02 purchase the upgraded clutch linkage from Corvette Central

 

Thanks for the help man, I found the old bearing and fork and there are a few differences... There is free play where the new fork meets the new bearing. The old fork has about 15mm between the pressure face of the fork and the back of the spring, which makes for just anice amount of tension in the spring when engaged in the 13mm recess of the bearing. The new fork has only 10 mm which leaves 3mm (1/8") slop in the bearing... Also the new bearing is not Centerforce, whereas the clutch is.
Current status - Clutch and flywheel at shops getting minor refacing done, while I wait for extended ball, Centerforce bearing and replacement spring for the original fork (this was all that was damaged - $7.50, but the plonker who rebuilt my gearbox, supplied me a whole new- crappy - fork...)
Once back together I am sure it will be fine - Then I can go and visit 'Expert' with baseball bat and new bill.......
My gallery is now up, I think it was just awaiting approval
Cheers

 

When you replace the spring on the fork use a rivet gun and bucking bar to rivet the spring to the fork. The rivet they supply is pretty soft but if you just try to hammer and dolly it into place you may work harden the rivet before its driven.
Find a aircraft mechanic at your local airport give him a six pack & I'll bet he'll do it while you wait. I took me all of 2 minutes to grind off old rivet and buck the new one.

 

Just by the fact that the guy didnt put a centerfoce bearing back in the first time , you can tell he is an idiot.

 

You got that right....
He was also meant to check the clutch while the box was out....
Didnt trust him there either, so I pulled it and yup...new clutch and pressure plate on their way (was cheaper than machining the plate and buying a new clutch in the end... , flywheel at shop getting a bit of a skim...
Now dropping sump to replace gasket while everything else out... damn - I hope I can stop myself soon

Anyone have advice on balance with new pressure plate??

 

You mentioned in your post you were waiting on the extend ball. I'm assuming you mean the clutch fork pivot ball? If so where did you order this from? I am having a similar problem. The original throughout bearing is to thick not allowing the clutch to fully engage and the replacement one is to thin (I had to adjust the clutch linkage all the way out just to have enough pedal travel to disengage the clutch. If I had an extended ball that would solve my problem.