The generator matrix

 1  0  0  1  1  1  X  1  1  X  1  X  1  0  1  1  X  1  X  1  1  1  0  0  1  X  1  0  1  1  X  1  1  0  1  1  0  X  1  1  X  0  1  1  1  1  1  1  1  1  0  X  X  0  0  X  1  1  1  1  1  1  1  1  1  1  1  0  1  1
 0  1  0  0  1 X+1  1  X X+1  1  0  0  1  1  X X+1  1  1  X  X  1 X+1  X  1  0  1  X  1  0  1  1 X+1  0  1  X X+1  1  0  X  1  1  0  X  X  0  0  1 X+1 X+1  1  1  1  1  1  X  X  0  0  0  X  0  X  X  X  X  X  1  1  X  0
 0  0  1  1 X+1  0 X+1  1 X+1  X  X  1  X  1  1  X  1  1  1  0  0  1  1  0  1  X  X X+1  0 X+1  1 X+1  X X+1 X+1  X  X  1 X+1  0  0  1  X  0 X+1 X+1  1  1  0  X  X  0 X+1  1  1  1  0  0  X  X  X  X  0  0  1  1  1  X X+1 X+1
 0  0  0  X  X  X  0  0  0  X  X  X  0  X  X  X  0  X  0  0  0  0  X  X  0  0  X  X  X  0  X  X  0  0  X  0  X  0  0  X  0  X  0  X  0  X  0  X  0  X  0  X  X  0  0  X  0  X  X  0  0  X  X  0  0  X  0  X  0  0

generates a code of length 70 over Z2[X]/(X^2) who´s minimum homogenous weight is 68.

Homogenous weight enumerator: w(x)=1x^0+19x^68+32x^69+24x^70+32x^71+10x^72+6x^74+1x^80+1x^84+2x^90

The gray image is a linear code over GF(2) with n=140, k=7 and d=68.
As d=68 is an upper bound for linear (140,7,2)-codes, this code is optimal over Z2[X]/(X^2) for dimension 7.
This code was found by Heurico 1.16 in 0.0815 seconds.