According to my book, a 1/2 ton pickup had 108" wheel base, but in 53, Dodge added a 116" wheel base 1/2 ton. Also, a 3/4 ton could/would have been 116" wb. The stake bed truck could have been either a 108" or a 116". Clear as mud, eh? Either way, I think the Dakota wb will work out great.

Just for your info, begining in 56 or 57, the step side box stake pockets became straight (read 1 1/2" or 2" square tubing) and begining in 53 through the end in 86 or 87, all step side fenders were the same (think LRE). Also in 56 or 57, the top ledge of the box side change from a 45 degree angle to a 90 degree angle. 1" conduit is about the same diamiter as the rolled tube at the top surface of the box sides. If a guy could live without the strengthing ribs in the box sides, some bent 18g or 20g sheet metal makes a nice box sides that can match any wheel base configuring. See my box in the picture above. Gene