I understand.
The front mounts of both cabs will be the same. I found the 48 cab mount holes to be just a little different than the 53. This could be remedied with a rat tail file.
The rear mounts on the 53 are two straps on each side of the frame.
The rear mount on the 49 (I assume it is the same as my 48) will be in the center of the crossmember under the back of your cab. It is kind of a swivel action mount. This crossmember going underneath your cab from side to side of the frame is drilled for this mount on the 48-49. You will have to mark and drill these holes on your 53 frame. This mount is bolted down on two places and on both sides of this swivel mount. The cab is also supported by two rubber bumpers on each sides at the back.
I hope this helps
