I have a 1997 GMC Sierra half ton 4x4 with the 350 V8 and my old battery died. I stopped by Napa as my buddy who is a diesel tech swears by Napa Legend batteries. The one they sold me has 700 CCA. Is this enough for my truck? The old one in my truck had 770CCA. The Legend Napa sold me was the best/strongest battery Napa sells for my truck. I did a search on how many CCA the factory battery had back in 1997 and nothing came up. Thanks for any advice!