Difference between Holley Terminator LS and Terminator X LS?

[protour_chevelle]

550-608 uses the Holley HP ECU Can support high and low impedance injectors, Bosch or NTK WBO2 sensors, dual WBO2 (Dominator only). Outputs can be positive or ground side triggers, internal datalogging, ability to do a System Log. (Stolen from a post of Andrews)

550-903 uses the newer plastic terminator ECU. Some limitations are high impedance injectors only, single Bosch 4.9 wideband O2 sensor, outputs are only ground side triggers, no internal datalogging, no ability to do a System Log.

Chances are the 608 uses a harness that is built in the USA, The terminator harness is typically made in China and comes with bad crimps, wires swapped, etc. Not all but definitely known for the lack of QC.

Both can't do transmission control.