I have an 11" bell housing/clutch assembly.
The clutch fork I installed during assembly turned out to be the wrong one. It was too long and didn't line up with the linkage.
I was able to remove it but now the correct fork does not want to go in.
Its very close but the pads that contact the throw out bearing on about 1/16" of an inch from clearing enough for the fork to slip onto the pivot bracket.
I cannot seem to apply enough force to the throw out bearing to make it clear.
One question I have is concerning the pivot bracket. Is it at 90 degrees to the mounting surface? Thought maybe it got bent slightly when removing the other fork.
I will be attempting to install the clutch fork when I get home from work to day. So if I don't reply right away that is why.

It's easiest to do with the transmission out. You're risking snapping a retainer clip at the T.O. bearing by forcing it in. I have an unused pivot. It's a beefy piece and wouldn't bend very easy.

Another Pic.

I was able to get the fork installed without removing the transmission.
It was a matter of getting everything aligned just right.
Thanks for the help.

Awesome! What linkage are you using? I switched to the truck style years ago and haven't had to replace anything since then. The plastic isolator kept wearing out throwing off my adjustment. Think I went through 3 of them.