Help with timing on 89 chevy with 4.3

Can anyone help me find the wire I need to unplug to set the timing on a 89 chevy 1500 with the 4.3 litre.   I need to get this figured out my truck runs like crap and gets horrible gas mileage! It already has new plugs and wires, I just never got the timing right after I replaced head gaskets. Thanks

BUMP... Anyone?

Sorry I cant help, here is a bump 

Bump again

bump on your forehead