will having an 85 ECU and a 86engine make any difference? or should it not make any at all? also i am looking to buy a good ecu from a pick and pull and it has a Brown cover ofer the prom chip and my current one has a black one any difference in the chip itself or just an different production batches thing. the ecu was pulled from a camaro idential to mine it was an auto and mine is an auto.