From the 2.3 engine you need to swap to the 2.6:
-all the accessories & brackets except use the 2.6 water pump pulley, all the smog stuff
-intake w/ carb, exhaust manifold if the EGR tube won't bolt up at each end
-distributor, maybe coil
-engine plate, fylwheel & clutch
-you will need to install an electric fuel pump, there is no boss machined into the 2.6 head for the 2.3 mechanical pump
-one motor mount has a different part #, think driver's side, but the 2.3 mount may work
That's all I can think of right now. The valve lash on a 2.6 is .008/.008, not .006/.010 like a 2.3. If your donor engine has the 4x4 2pc oil pan you may need to use the 2.3 oil pickup tube- don't forget the gasket.
'78 Chevy LUV,1.9,4sp,headers,31's,SAS Dana 30,Dana 20,SOA rear w/Aussie Locker, body ROUGH, bought new 12/4/78. A pre-P'up?
'87 Trooper,2.3,5sp,headers,31's,ball joint flip & spacer,Aussie Locker rear,Superwinch hubs,brush guard w/5.5K winch.