Hot Rods Difference between 1946 and 1948 F1 truck frame

I'm thinking about putting a MII front end under my 46 Ford truck. There are lots available for the 48-52, but not many can be found for the 42-47 frame. I would like to buy one of the bolt in cross members, but can find any of those for the 42-47. Does anyone know if the difference between the frames?. Looking at them they appear in pictures to be the same

 

The frames are the same. I put one of the first heidts crossmembers for a 48-52 under a 47 frame.

 

Thanks. Just checking out the pictures, they sure look the same.