The generator matrix

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

generates a code of length 64 over Z8 who´s minimum homogenous weight is 54.

Homogenous weight enumerator: w(x)=1x^0+90x^54+240x^55+507x^56+830x^57+1192x^58+1666x^59+2017x^60+2302x^61+2884x^62+3126x^63+3102x^64+3208x^65+2850x^66+2488x^67+1987x^68+1526x^69+1114x^70+656x^71+436x^72+224x^73+146x^74+70x^75+44x^76+36x^77+12x^78+10x^79+2x^80+2x^81

The gray image is a code over GF(2) with n=256, k=15 and d=108.
This code was found by Heurico 1.16 in 36.5 seconds.