'72 114 distributor...

ok, have a '72 250 with the dual zeniths.
been parked for 2 1/2 yrs with a bad head.
finally finished all the top-end work and put it back together.
it made it 4 blocks before dying. when i checked for spark, it had none.
when i checked the distributor i find it does NOT move!!
Any Idea what would cause this?
I assumed the timing chain snapped, but the cam still moves and the compression does not sound off.
so...what now???

tanx.

~Robert