I'm probably going to locate my battery in the bed and not underneath. I sometimes take my truck off road and want to make sure its protected. I might go with a sealed battery box from jegs or summit. Should I run the ground cable back to the engine block?``

 

the stock negative cable that runs from the engine to the batt, ground that to the frame. when you relocate the battery to the bed, run your negative cable from the batt. to a ground on the frame.