Really, you have to have a 97 timed via a computer/scanner? What ever happened to the nice timing light that everyone could afford? I think the dealership/parts store, along with my husband are full of hooey that that ONLY way to time a 1997 1500 series Silverado 5.7 350 is with the scanner/computer hook up and then the truck's computer times itself once you are 0 (+/-). What year did this start and when does it end??!!!!!