Can I go to a 3:73 gearset on the same carrier as my 3:21 carrier in the 9 1/4 and Dana 44 in my ramcharger?

The Carrier Break for the Dana 44 is 3.73 and down, 3.92 and up, so you should be Ok on the Dana 44. From all I have read, the Chrysler 9 1/4 doesn't have a carrier break, so supposedly any ratio will fit as there is only one carrier, but you might want to get this verified by which ever gear vendor you choose or someone else here on Moparts will likely know for sure.

You can look up the information by Google'ing "Carrier Break" for the model in question.

Here is an example of results:

West Coast Differentials Tech Info

the 9 1/4 axle and c-clip change in 85 with the wbp change to 5 on 5.5

may be in the mix for a new carrier as well if it needs a tone ring for abs.

THANKS GUYS