The generator matrix

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

generates a code of length 78 over Z8 who´s minimum homogenous weight is 70.

Homogenous weight enumerator: w(x)=1x^0+121x^70+184x^71+512x^72+420x^73+765x^74+672x^75+689x^76+612x^77+651x^78+552x^79+697x^80+508x^81+549x^82+368x^83+296x^84+172x^85+162x^86+80x^87+94x^88+16x^89+44x^90+11x^92+10x^94+4x^96+2x^98

The gray image is a code over GF(2) with n=312, k=13 and d=140.
This code was found by Heurico 1.16 in 3 seconds.