yes it has an adjustable pulley. I no my piston does not come up that far seen as I rebuilt the engine and had it back in bits, I am sure I would of noticed if the piston came above the block and there are no marks on the old gasket. as for timing issue's not sure, but if fell very confident in what motor scope Northallerton have done when they set it up.
so far there seems 2 be a lot of people and talk about head torqueing most likely being the cause, or hopefully a crap gasket.
I am hopefully going out in the car this weekend I will keep you all informed.
thanks again for your help