[dsraven]

I would think, looking at your project on another thread, that a battery inside would be just as hard to access as a battery under the bed or under the floor of the cab. even if the seats were slid all the way forward and tipped ahead you still need to get the dang thing out from behind the seats. sounds like a back strain to me. how about a battery tray frame mounted in behind the filler panel from the box to the running board, any room there for an access door? a trap door in the box floor? some sort of mechanism to allow the frame mounted battery tray to come down to the ground level, possibly an electric linear actuator? personally I think the shiny alum checkerplate box looks too modern for the look of the truck. that's just me though. an old rounded corner coleman cooler would possibly look more era correct if you could find one, or make something like that.
oh, I got it! a hydraulic tilt truck box would allow access to anything under the box. solved!
lol.