Originally Posted by ParaWK4

Wondering if the cogs on the new style Shimano freewheels with the lockring will fit on an old Shimano 600 or Dura Ace freewheel body. I am thinking of disassembling a new freewheel to use the inner cogs to fill in worn cogs and keep an old freewheel body on the road. If they do fit, I assume I would have to use the outer threaded cog to hold it together. I also expect there would be shifting differences with mixing old and hyperglide cogs, but I am friction shifting so ok with that.