Hot Rods Who knows what this is?

Can anyone tell me what I have here? The tooth count is 40 ring, 11 pinion (3:64 ratio?) I was informed that it might be from a 49-53 ford. What do you think?
Thanks! Joe.
Zero Budget Racing

 

It does look 1949-1954 Ford

 

...and the ratio is 3.70:1.

 

40/11=3.63[6363636363infin] 1949-56

 

I get 3.64:1 rounded up from 3.63636363.....