u should have the L8
L6 is from rwd cosworth (sapphire) and it´s has a mounting flange attach to it.
L8 (iaw 048/01) comes from 4x4 sapphire and it´s has no mounting flange
L6 has 64Kb memorystorage and L8 has 128Kb
L8 has HEGO and knock sensor output (and some boxes has just the knocksensor (iaw048/02))