The last sentence in this page describes the difference from 47-48 and 49-50 cab mounts. http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0101.htm
After that change the cab mounts stayed the same through 54. So the cab will fit, if it is from 49-54. The doors were changed to the wing type in 51. Push button door came in..52? I think. The doors will fit as far as I know into any year cab.

Last edited by Steve_H; 03/15/2016 3:55 PM.

Steve H