Thanks for the suggestions. Like Moisheh, the hitch places I've talked to say no. Blue Ox warns that doing so will lower the towing weight and most shops just won't take that chance. I don't have the equipment to do it myself, hence the original question about the two different shanks. There is $100 difference. I would just as soon not spend it for something I don't need. After all, there is always another place on an RV that does need it!
George & Karen with 3 Border Collies
2015 Winnebago Journey 40R
2015 Ford C-Max