Question for anyone who might be able to help...

My friend has a 98 Civic CX that he's getting ready to donate to Goodwill. I have a 93 Civic CX that the engine's starting to give me some trouble with. My question is:

I know I can put his d16y7 in my car, but is it possible for me to put my d15b8 in his car so he still has a functioning car he can donate? And if so, what needs to be swapped from each car (ie; tranny, axles, ecus, etc.)?

And would it be worth the effort? I noticed there appears to be alot more you can do with a d16 than a d15.

TIA!