I have a similar interest in putting duals on the rear of my 50 3600 pickup. (You have a cool 49 3600 btw.) I need to do some measuring first. I can see that the fenders will have to be widened but I need to look at the inside clearance closely too. I know there is a spacer/adapter that bolts to the front hubs to use a dually wheel. Maybe 16" dual wheels will work. Do you have the 15" detachable rim type wheels? Maybe somebody else can help. Let us know what you come up with.
