UP FOR AUCTION WE HAVE A 1977 GMC/CHEVROLET TRUCK WIRING DIAGRAM MANUAL. THIS IS THE WIRING DIAGRAM A GMC/CHEVROLET MECHANIC WOULD HAVE USED TO WORK ON A 1977 GMC/CHEVROLET TRUCK. THIS IS GOOD ORIGINAL MANUAL. NOTE PICTURES FOR CONDITION. PLEASE FEEL FREE TO ASK ANY QUESTIONS PRIOR TO BIDDING. SHIPPING WILL BE $5.00 VIA USPS AND WILL INCLUDE A TRACKING NUMBER. THANK YOU FOR LOOKING AND HAPPY BIDDING!!!