Trying to figure out where my running board gaskets install. They are just over 3 feet long, 2" flat with a 1" lip. The area from the back of my front fender to the front of my back fender is just over 5 feet (I have the long bed). Where in this space does the gasket go? Up toward front fender or in the back? Or do I have the gasket for the 1/2 ton bed? However 3' does not seem long enough for a half ton either? My '38 running board is over 4 feet. Help, please. Thanks!!!!