bought a 2007 silverado 2wd 4.8 with 15,000 miles to install in my 2008 silverado 4wd which came with 4.8. Changed oil pan and motor mounts. Crankshaft sensor on 2008 is on front and 2007 is on back. Re-routed wire to back. Truck will not start. Will it need to be re-programed
