I just uploaded both versions that I have into /incoming, I believe the BUA9340 version was the original calibration in my 86 Vette that was built on 10/85 (Z51 auto 3.07 axle ratio). Dave D. >I found two BUA chips: >BUA9340 - 1986 5.7L (released 8/85) >BUA1728 - 1986 5.7L (released 7/86) >Don't have copies of either. >HTH >Mike V