What computer to use for EFI in my Dart

Thats what is commonly referred to as OBD I, the OBD II has the ability to accept quite a few programming mods via ALDL port or what most call the scanner plug. OBD II is 96+ and can be easily modified via SCT tuner file through the ALDL plug or a "bench flash" or "hard flash" . I would recommend a SCT "soft flash" as its less invasive to pcm internals. You will need a 96+ harness and pcm to make it work.