all rb blocks will fit any rb gearbox.
the difference's in the different capacity blocks ar the deck hieght above the main horizontal water jacket on the exhaust side(row of frost plugs) and internal stroke.
the instrument cluster is another rarley thought of one.....get the r33 instrument panel and disassemble, change the actual instruments over as they will fit into the r32 cluster housing..
there is a pin on the back of the clock on the speed, slide it out and match it to the Km's done on your 32 speedo
the pinout diagram for the loom can be found at
meggala.com skyline information
this will show you which wires you need to join from the r33 engine loom to the r32 dash loom.
you will need to buy a r33 top radiator hose.
as the 20 manifold is different to the 25.