Update the LT-5 is now running thus using a 1994 ECM, 1990 wiring harness and no CCM is workable.
The 94/95 ECMs of ZR-1 have a faster processor and uses a 16 bit bus rather then the older ZR-1s have a 8 bit bus.

This helps in performance since the ECM has more clock time to make adjustments faster
Also may even be harder finding 1990-93 ZR-1 ECMs thus 1994 ECM could be used.