Would a 22R-E out a 92 pickup with a auto tran fit in a 84 4x4 pickup with a 21R-U and a manual trans? I would like to keep the current manual trans in the 84 pickup if possible.

 

21R-U is a japanese crate motor.

In terms of will it bolt in? Yes absolutely. Will it plug and play? Its impossible to know that without first knowing what the PO did to your truck. The 84 is going to be carburated, and the 92 is fuel injected so unless you have the 92 donor truck and a lot of time to swap the fuel injection pieces over, I would look for a carbbed motor.