Is there any difference between the sohc and dohc blocks, i.e can a sohc head be put on a dohc block?

nope totaly diffo

What about the con rods?

No, they are different big end size and width.

bu**er! Injection rods are getting rare.

Wasn't there talk of diesel rods fitting?

yes the diesel rod are from a diesel fesster but they need a lot of work also the crank need regrinding to a smaller big end diameter
lots of work
are transit rods the same as injection rods as i have a set
cheers dave