The generator matrix

 1  1  1  1  1  1  1  1  1
 0  X  0  0  0  X  X  X a*X
 0  0  X  0  0 a^6*X a^5*X a^4*X a^4*X
 0  0  0  X  0  X a^5*X a*X a^3*X
 0  0  0  0  X a^6*X a^3*X a*X a^5*X

generates a code of length 9 over F8[X]/(X^2) who´s minimum homogenous weight is 40.

Homogenous weight enumerator: w(x)=1x^0+882x^40+1764x^48+7812x^56+229376x^63+12411x^64+9898x^72

The gray image is a linear code over GF(8) with n=72, k=6 and d=40.
This code was found by Heurico 1.16 in 1.49 seconds.