I have a 79 f150 with a 351M i am having troubles with the engine i can get it to start but it don't idle i bought it a month ago and the previous owner cut all the vacuum line off so i replaced they as good i a could. but the problem is when the truck is started the motor is jumping then eventually dies if i do not rev the engine so what could be the cause of this?

 

Sounds like you might have missed a vacuum line.Make sure the one on the dist. is on.Also check that your plug wires are in the correct firing order.

 

Check the Dist. Pick up valve. Had the same problem. I just put a new Dist. On the truck itself. Cheaper route would be just to replace the pick-up valve on the Dist.