The generator matrix

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

generates a code of length 78 over Z8 who´s minimum homogenous weight is 68.

Homogenous weight enumerator: w(x)=1x^0+130x^68+490x^69+665x^70+1014x^71+1525x^72+1550x^73+2082x^74+2410x^75+2490x^76+2658x^77+2738x^78+2920x^79+2572x^80+2366x^81+1953x^82+1616x^83+1339x^84+860x^85+544x^86+322x^87+230x^88+120x^89+71x^90+38x^91+29x^92+16x^93+9x^94+4x^96+4x^97+2x^98

The gray image is a code over GF(2) with n=312, k=15 and d=136.
This code was found by Heurico 1.16 in 42.9 seconds.