I could have sworn the stock map sensor was a 3 bar cause when i raced turbo dodges one of the upgrades was a 3 bar map and everyone was using grand national stock map sensors also in all the stock car upgrades never said anything about upgrading the map sensor..Gm high tech is doiung a buildup on a stock 106,000 mile gn with dyno and drag strip numbers the current issue dosent show it but the previous two issues are the beginning and second installment very informative you combo needs a fuel pump, injectors with matching chip, lt1 valve springs, and something to help your 60 ft...The The only reason the dodges needed a different map sensor is that they had a 2 bar sensor and after so much boost the sensor was maxxed out and the ecm wouldnt know how much boost was coming into the engine