You have a 4.11 rear rear end.

The 3.55 conversion kits all come from Patrick\'s Antique Cars & Trucks . It is a a good idea to also buy the Ring & Pinion and the Ring & Pinion Installation Kit. The kit has all the bearings, bushings, clips, and gaskets that you really should replace.

If you do not have a runout gauge available, Harbor Freight not has a dial indicator and magnetic gauge holder on sale. Page 15 of the Tool Disposal Notice catalog - good until 26 March