The generator matrix

 1  0  1  1  1 X^2+X  1  1 X^2+X  1  1  0  1  1 X^2  1  1  X  1  1  1  1 X^2  X  X  X  0  1  1  X X^2  X  1  1  1  1  1  1  1  1 X^2  1  1
 0  1 X+1 X^2+X X^2+1  1  0 X+1  1 X^2+X X^2+1  1 X^2 X^2+X+1  1  X  1  1 X^2  X X^2+X+1  1  1  1  0 X^2+X  X  0 X^2  X  X X^2 X+1 X^2+1 X^2+X+1  1  0 X^2 X^2+X X^2+X X^2 X+1 X^2+X+1
 0  0 X^2 X^2  0 X^2 X^2  0  0  0 X^2 X^2 X^2 X^2 X^2  0  0  0  0 X^2  0 X^2  0 X^2 X^2 X^2 X^2  0 X^2 X^2 X^2 X^2  0  0  0  0 X^2  0  0 X^2 X^2  0 X^2

generates a code of length 43 over Z2[X]/(X^3) who´s minimum homogenous weight is 42.

Homogenous weight enumerator: w(x)=1x^0+72x^42+38x^44+14x^46+2x^54+1x^56

The gray image is a linear code over GF(2) with n=172, k=7 and d=84.
As d=85 is an upper bound for linear (172,7,2)-codes, this code is optimal over Z2[X]/(X^3) for dimension 7.
This code was found by Heurico 1.16 in 0.0242 seconds.