wow,well ur dash guege wires come out throu firewall,oil pressure at the sender,,tach is your coil wires and the temp guage is on front of engine,,but doesnt matter cause the eec gets it from left side of motor abouve the water pump,,they guy probly used the power wire comin off the altenator for the 6al,,try goin to computer and find the green clip that sends power to the computer from the body harness,,should be behind the glovebox,,u should be able to follow that back to the fuse box,,,but if he rigged it,it might go back to ignition swith,,do u know what the guy ran engine wise befor you,