Just for future reference when you're pulling these ECM's, The EEC-IV ECM's all have EEC-IV on the tag. Speed Density ECM's are marked with SFI-SD1 or 2 or 3, depending on the revision. MAF versions are marked with SFI-MA12 or 12A, again depending on revision. Your DB1 is marked SFI-SD1. The DX3...