The generator matrix

 1  0  0  1  1  1  6  4  1  1  1  1  2  6  1  1  1  4  6  1  2  1  1  2  1  1  4  4  2  2  1  6  1  6  1  1  0  1  1  1  4  1  1  1  0  0  6  2  1  2  1  1  1  1  0  1  1  1  1  4  1  4  4  0
 0  1  0  0  1  1  1  1  6  3  2  5  1  0  7  4  1  1  6  0  1  7  4  1  7  2  2  1  1  0  7  1  3  6  6  2  1  5  4  4  0  1  2  7  1  1  1  1  7  2  2  2  3  5  1  4  1  7  0  0  3  1  1  1
 0  0  1  3  3  0  3  7  3  0  4  5  2  1  1  2  6  2  1  5  1  2  4  2  3  1  1  5  7  1  4  0  1  1  4  7  3  3  6  5  1  6  5  7  2  7  0  3  6  1  1  2  0  6  5  5  1  5  6  1  1  7  2  6
 0  0  0  4  0  0  4  0  0  4  0  0  4  4  4  4  4  4  4  4  4  0  4  0  4  0  4  0  4  0  0  4  0  0  4  0  4  4  0  4  4  4  4  4  0  4  4  0  4  4  4  4  4  0  0  0  4  4  0  4  4  0  4  0
 0  0  0  0  4  0  0  0  0  0  0  0  0  0  0  4  4  4  4  4  4  4  0  4  4  4  4  0  4  0  4  4  4  4  4  0  0  4  4  0  0  0  4  0  0  0  4  0  4  0  0  0  0  0  4  4  0  4  0  4  4  4  0  4
 0  0  0  0  0  4  4  0  4  0  4  4  4  4  0  4  4  0  0  4  0  0  4  4  4  0  4  4  4  4  4  4  4  0  0  0  0  0  4  4  4  4  0  4  4  4  0  4  0  0  4  0  4  4  0  4  0  4  4  4  0  4  4  4

generates a code of length 64 over Z8 who´s minimum homogenous weight is 58.

Homogenous weight enumerator: w(x)=1x^0+201x^58+204x^59+430x^60+376x^61+487x^62+264x^63+520x^64+244x^65+391x^66+208x^67+241x^68+116x^69+151x^70+88x^71+75x^72+28x^73+36x^74+4x^75+13x^76+4x^77+14x^78

The gray image is a code over GF(2) with n=256, k=12 and d=116.
This code was found by Heurico 1.16 in 0.891 seconds.