My prop shaft seems to quite short, it's out if a four wheel drive cosworth if that makes a differance. I've not got the adapter on the end yet, but it's about 8" from the engine. I've been told some shafts extend but mine seems fixed. Any ideas.

I think you've got muddled up somewhere.

The propshaft is usually made specific to your car so the sierra one won't fit. The driveshafts are standard sierra lengths.

[Edited on 21/4/14 by Ben_Copeland]