i bought the biggest one i could find, partially because i had ooold wiring and i didnt have the best of conductivity, i think it was 1000 CCA and 1100 CA(had to shop around quiote a bit). But my dad tells me stories of how he used to buy marine boat batteries and put them in his muscle cares(corvettes and trans ams). Sounds like overkill to me but he still thinks its the best way to go