hi im a new user to this site but i need help with my 1978 350 4 bolt main in my 1977 chevy 1 ton we had it running about a week ago it was running great better than what we thought it would......then it ran out of gas we filled it up and then it wouldnt start.....we where getting fuel we checked the spark and again we where getting it so our next thought was timing and we were kind of right we got it to fire but it was running half the rpm as it was a week ago and we only got it to fire a couple times before it stoped for a while if you guys could give me suggestions I would appreciate it. thank you