I also have a 56 Merc and have discussed this a few different times with the Borgeson folks at various NSRA and Goodguys shows. They will not certify that the 56 Ford kit will work, but say that it should work on some early Merc’s, but they didn’t know up to what Serial #. Only way to know for sure is to take it our and compare to a 56 Ford box to see if the brackets, etc match. This conversion is not a good idea if you are keeping the Stock Steering Column as you have to cut your column to be able to connect to the new box. I think it would be much cheaper to rebuild your existing unit.
Thank you Norm I did do a little adjustment on the steering box and it did help.I ll take your advice and wait till I need to have the box rebuilt.Next project is front and rear springs from Eaton Detroit Spring Inc.