I may be screwed...Here is the return email I received...
HI PAT, WE MAKE A LADDER BAR BACK HALF KIT. THE REAR HOUSING FOR THAT FRAME IS 38”1/4 HOUSING END TO HOUSING END.43”1/4 AXLE FLANGE TO AXLE FLANGE. WE CAN CHANGE THE REAR WIDTH BUT I DON’T KNOW IF WE CAN CHANGE IT TO WORK WITH YOUR WHEEL. YOU WOULD HAVE TO TAKE SOME MEASURMENTS AND SEE HOW WIDE THE REAR HAS TO BE AND WERE THE FRAME WILL END UP.THE FRAME MEASURMENTS ARE 27”5/8 OUTSIDE TO OUTSIDE. ANYTHING ELSE I CAN HELP YOU WITH LET ME NO. THANKS