w/o any label info I do not know a way to identify it from the outside, the shell, connections, and pins are identical (both have all pins in the connectors) . As Rob said in post #2 there may be some info on the label. If you have the Broadcast Code (BCC) piece of the label it's a 4 letter code starting with a 'B' that may help. assuming it's LT1 with 4 connections (blue,black,grey,red) If you have OBD1 and OBD2 scanner capability or software and a cable you can always install it and see with key on / engine off which interface connects.