I have an 85 with a 305 in it. I have just installed the motor.Somebody else did a rebuild on it before I got it. I cannot seem to get it to idle. Seems to run OK when I keep on the gas but every now and than it back fires and pops. I was i told it may be my timing? thoughts on-that anybody! my next question is I never have timed anything. I can get a timing light but have no idea how to do it. About all i know about timing is turning the distub one way or the other. Can someone post this in detail for me. Also I am not driving the truck at this time as it is no where near ready for the road.