Sorry Col, Southampton is a bit far from Lancashire or I would have gladly come round to help.....don't drink so your beer would have lasted you a bit longer
Second best is that I can help you with the timing from afar.
After the timing cases are removed and before you strip off the head...set up the timing first.
You need 3x8mm threaded 2 to 3 inch long bolts and a pin to lock the crank at the flywheel and some tippex or a dab of paint.
Turn the engine until the bolt hole in the cam pulley lines up with a screw thread in the head when the 2 holes in the injection pump line up with the screw threads on the pump at the same time.
Screw a bolt through the cam pulley into the head to lock the cam pulley.
Screw the other 2 bolts through the injection pump holes to lock the injection pump.
Up behind the starter motor is a hole where you push a pin into the flywheel to lock the crank, push in your pin and lock the crank.....not that easy.
Using tippex or paint, mark the teeth on the bottom pulley where the timing belt fits on and mark the block in case the bottom pulley happens to move if the crank locking pin hasn't gone in properly.
Now you can release the tensioner and lock it back against spring tension so that you can remove the timing belt.
When you are fitting the head set the cam position so that the bolt on the cam pulley screws in at the right spot....take a picture of where the cam lobes are set when the locking bolt is in before you strip off the head so that you know for sure the correct position when you fit the new head.
Good luck, I hope this helps
