Marlin 60 assembly fun

[terraformer]

I have this marlin 60 I offered to fix for my nephew. It is an old style and I bought the conversion kit since one of the parts I needed was the feedthroat and old style parts are not as common. Has anyone done this? If so, did the the feedthroat come with an extra stud on it? This was supposed to be drop in but I am finding 4 studs on the feedthroat and 3 holes to fit them into. The older feedthroat has 3 studs.
Do I make a hole, or file off the 4th stud?