This can be tough. You should be able to see inside the side gears. Count the number of valleys. Dana 44 axles have 30 splines, AMC 20 have 29. There should be a like number of valleys (gaps between teeth) in the side gear. This site might help: http://www.oly4x4.com/factoryaxleguide.htm This site will help if you have the full axle: http://www.jeeptech.com/axle/amc20.html IIRC 2.87 is the cut-off for the "2" series carrier. Jeeps never used a 2.87 -- as far as Jeepers are concerned the 2.73 carrier only supports a 2.73. That carrier should support all 2.25-2.87 gears. The very high 2.21 gears used in some late 80s cars had it's own carrier due to the large diameter pinion gear (19 teeth, respectively). Typical 2 series carriers have 15-17 tooth pinion, 40-43 tooth ring gears (2.21 has a 42 tooth ring). The diameter of the pinion affects the offset of the ring mount on the carrier. The ring gear can only be so thin! 3.08-3.73 gears use a 3 series carrier (11-13 tooth pinion), and 3.91-4.56 a 4 series (9-10 tooth pinion). Note that some aftermarket companies use thicker ring gears or spacers to provide ratios not supported by the factory for some carriers. The gear ratio ranges I provided may not be 100% accurate -- I'm working from memory here! The gear providers will be able to tell you what will fit as long as you know what was originally on the ca rrier. ---------------------------------------------------- Date: Wednesday, May 2, 2007 06:55 AM From: Armand Eshleman <aje1@xxxxxxxxxxxxxxx> Still on that 2.73 ratio stuff. Is there a way to positively identify which twin grip differential one has? Remember I only have the differential and the guts for it. I do not have the rear end. I thought it prudent to actually find out what part I have, before ending up with incompatible pieces. I understand that this differential will not fit other ratios. Is that correct? -- Frank Swygert Publisher, "American Motors Cars" Magazine (AMC) For all AMC enthusiasts http://farna.home.att.net/AMC.html (free download available!) _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list