I love the Nissan spare tire carrier idea.
You stole my name. Waa.
From the looks of the grease fittings in the control arms, I think you may want to get out the grease gun and find all the zerks, then pump grease in til clean comes out. You might need a manual to tell you all the grease points.
For the person who asked about bed wood dimensions see the link for some info. Bed Wood Dimensions - Cutting wood to fit MAR-K bed strips
http://www.mar-k.com/index.php?p=tips-and-tricks
Found another.
http://www.gmcpauls.com/47-72_BedWood_Info.htm