The generator matrix

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

generates a code of length 77 over Z8 who´s minimum homogenous weight is 71.

Homogenous weight enumerator: w(x)=1x^0+168x^71+349x^72+436x^73+458x^74+380x^75+352x^76+358x^77+282x^78+222x^79+239x^80+180x^81+158x^82+148x^83+106x^84+86x^85+74x^86+38x^87+23x^88+28x^89+4x^91+2x^92+4x^94

The gray image is a code over GF(2) with n=308, k=12 and d=142.
This code was found by Heurico 1.11 in 0.513 seconds.