v8 clutch problems

Hi all,
I am having problems with my 1966 11a v8.
Just replaced the gear box,presser plate, clutch plate and release bearing and now the clutch will not work.
Its a 11a box with a 111 bell housing and clutch.
Pulled it apart and noticed that the release bearing is shorter than the original one.
I guess that the original one is longer to allow for the thickness of the adapter plate bolted to the engine?
Could any one tell me if this is correct and if so where do i get one from?
Thanks.

You get two lengths of release spigot on the release bearing depending if you have a rangey or sd1 flywheel. Last time I think Steve Parker or the likes can sell you the right part.