What's the trick?  ZX fan is deeper to keep off the radiator I have, '77, '78 3 row.  Do I need a ZX fan clutch to get the clearance?   The ZX fan has an extra blade that has to help pull more air.

Thanks to anybody that has figured this out for a reply.  I'm stumped and not feeling too FAN-tastic. 

Check the way it's bolted on.  It may be flipped on the ZX.  I can measure back of blade to head if you want on my 80zx.