GX6000000 or GX7000000
Serial number will always start with G. Second digit (letter) indicates month. Stamped code runs through the middle of the bottom bracket and have month stamped as A, B, C, D, E, F, G, H, J, K, L, M for Jan to Dec. Rolled code runs around the edge of the bottom bracket and have month stamped as N, P, Q, R, S, T, U, V, W, X, Y, Z for Jan to Dec.
Third digit (number) indicates year of production (6-1996 or 7-1997). 1996 made frames built between Jan and June would be 1996 models. 1997 made frames built after June to December would be 1998 models.