90sAccords!

So I just "rebuilt" my F22B2 engine. Stripped it all the way down to the pistons and the gearbox cover, and either replaced or hand restored everything in between.
On assembly, First problem was that the crankshaft wouldn't turn. Pistons were just a little rusty, so I gave it a good yank with a pair of vice grips. After a few turns it recovered from having a little resistance.
So I put the head back on, which had been previously disassembled and cleaned up. Put on my timing belts and tensioned them. And now my camshaft won't turn..
I just used motor oil when I assembled the head.. also changed the head gasket obviously. Everything is torqued to spec and the crankshaft, front balance shaft, oil pump and water pump are all turning fine.
I'm yet to fill her back up with oil and coolant, but before I even bother, is there any reason that I haven't thought of that the cam won't turn?

Update: I did add oil and lube everything up. Still no rotation at the cam.