So should I still make the bumper out of heavy wall pipe ? I know it would be better in an accident but sheeeees you guys are making me rethink everything...lol Right now the fuel cell and battery are the furtherest back in the bed they can go. The horizontal center of weight of these two is higher than the horizontal center of the engine. I had a thread about that placement as well and got some great feed back. Here's a look at the back of things.