Classic/Antique Car Repair: Engine wont crank, 1970 chevy c10, acting this way

Question
I have a 1970 Chevy c10 truck with a 307 engine.  The engine will turn overand sometimes crank up but is rough.  You have to keep giving it gas to keep it running.  The distributor can be turned almost an inch....is this normal?  It has a bolt that I assume can be tightened to lock the distributor in place once time has been set.  Question is....is this the reason motor is acting this way?

Answer
Hi Dunaway;
       Well if the dist. is turning that much - it is bad as it is not to turn at all. once the timeing is set it should be tight so it can not move at all-- also I hope that the dist. was not removed at all , if yes than it will have to be re-set on no #1   tdc. but if it was never taken out
than it must be timed and than the  bolt  tightened  so it will stay in place , it might just need a set of pionts & cond. cap, rotor , plugs and filters , a good tune up never hurt any motor.