Rear Shocks
Looked on Rockauto and basing this off KYB shocks. The extended length of a 2000 Dakota 4wd rear shock is 25.39", compressed is 15.16". 2wd is 23.43" extended and 14.17" compressed
The 72 duster rear shock extended is 21.57", and 13.39 compressed.
Hope that helps
So I think you will be fine with the Dakota shocks.