The generator matrix

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

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

Homogenous weight enumerator: w(x)=1x^0+140x^58+294x^59+413x^60+358x^61+527x^62+322x^63+375x^64+324x^65+354x^66+198x^67+236x^68+142x^69+123x^70+86x^71+81x^72+56x^73+40x^74+12x^75+13x^76+1x^80

The gray image is a code over GF(2) with n=256, k=12 and d=116.
This code was found by Heurico 1.11 in 0.369 seconds.