Best way to quickly tell is by the Inlet manifold (IM)Ö. make sure itís not the EUNOS 800 (curved neck and all together rounder looking); It can be a problem fitting in the MX6.
The ZE IM has a longer straighter neck to the TB. (not curved forward at 45 degrees like the KLDE). And has a ďhumpĒ going North West in the centre at the back.
Iím sure we can dig you up some pictures if you donít know what they look like..
But be wary as the KFZE has the same looking inlet manifold so make sure you check the following
The throttle body Should read KL31
The heads, One should read KL31-101 and the other KL31-1A1
The CAMS: Should read KL-31
The PISTONS should be flat (not concave) kinda hard to spot this one but if you pull a spark plug and shine a light down in there to see the top of the piston. But if the others are correct chances are this will be to.
good luck mate...
Oh and see if you can scam a Kl31 ecu and JE50 vaf
If you aren't living on the edge...Your taking up to much space..