The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  2  2  2  0  4  0  2  2  4  1  1  2  0  1  1  4  2  1  1  1  1  4  2  2  4  1  1  1  2  1  1  2  1  2  1  0  2  1  4  1  4  1  2  1  1  0  2  2  0  2  2  1
 0  2  0  2  0  0  2  6  0  0  2  6  4  6  4  6  4  2  0  6  0  0  2  2  0  4  2  6  4  2  0  2  6  2  4  4  2  2  4  2  2  0  6  6  2  0  2  2  0  0  2  4  6  2  2  4  2  0  6  6  2  4  4  0  4  6  2  0  4  0  2  4  0  2  2  2  6  4  2  2  4  0  0  0
 0  0  2  2  0  6  2  0  0  6  2  0  4  2  2  0  6  6  4  0  4  6  6  4  2  4  2  0  2  2  4  4  0  2  2  2  2  0  2  2  6  4  4  4  0  6  6  6  6  4  4  4  0  2  6  2  6  2  2  4  6  6  6  2  2  0  6  2  6  0  0  4  2  0  4  6  6  2  2  6  2  0  0  0
 0  0  0  4  0  0  0  0  0  0  0  0  0  4  0  0  0  0  0  4  4  4  0  0  0  4  0  4  0  0  4  4  4  0  4  4  0  0  4  0  0  4  4  0  0  0  4  4  4  0  0  0  4  4  0  4  0  0  4  4  4  4  0  0  0  4  4  4  0  4  0  4  4  4  4  0  4  0  4  4  4  4  0  0
 0  0  0  0  4  0  0  0  0  0  0  0  0  0  0  0  0  0  4  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  4  4  4  4  4  4  4  4  4  4  4  4  4  4  4  4  4  4  0  0  0  4  4  4  4  4  0  4  4  4  4  4  0  4  0  4  4  0  4  0  4  4  0  4  0
 0  0  0  0  0  4  0  0  0  0  0  0  0  0  4  0  4  0  0  0  0  4  0  0  4  0  4  4  0  4  4  4  0  4  4  4  0  4  0  0  0  0  0  4  4  0  4  4  0  4  4  0  4  0  4  0  0  0  4  0  4  4  4  0  4  0  4  4  4  0  0  0  0  0  4  0  0  0  4  4  4  0  4  0
 0  0  0  0  0  0  4  0  0  0  0  0  0  0  0  0  0  4  0  0  0  0  0  4  4  4  4  0  4  4  0  4  0  0  4  4  4  0  4  4  0  0  4  4  4  4  4  0  4  0  0  4  0  4  0  0  0  0  4  4  4  0  4  0  0  4  4  4  0  0  0  0  4  4  4  4  0  4  4  0  4  0  0  0
 0  0  0  0  0  0  0  4  0  0  0  4  0  0  4  0  0  0  0  0  0  4  4  0  0  4  0  0  0  4  0  0  4  4  4  4  0  4  0  4  0  4  4  0  4  0  0  4  0  0  4  4  4  4  4  0  0  4  4  4  4  0  0  4  0  4  0  0  4  4  4  0  0  4  0  0  4  4  4  0  4  0  0  0
 0  0  0  0  0  0  0  0  4  0  0  0  0  0  0  4  4  4  4  4  4  0  0  4  0  0  4  4  0  4  0  0  4  0  4  4  0  4  0  4  4  4  4  0  4  0  4  0  0  4  0  0  4  0  0  4  0  0  4  0  4  0  4  0  4  4  0  0  4  0  4  0  4  4  0  4  4  4  0  4  0  4  4  0
 0  0  0  0  0  0  0  0  0  4  0  4  4  4  0  4  0  4  0  0  0  0  4  0  0  0  0  0  4  4  4  4  0  4  4  4  0  4  0  0  0  4  0  4  4  4  4  4  4  0  0  4  0  0  0  4  4  0  0  0  4  0  4  4  4  4  4  4  0  4  0  0  0  0  0  0  0  4  0  0  0  0  0  0
 0  0  0  0  0  0  0  0  0  0  4  0  0  0  0  0  0  0  0  4  4  4  4  4  4  0  0  4  4  0  4  0  0  4  4  0  4  0  0  4  0  4  0  4  0  4  4  0  4  4  0  4  0  0  4  4  4  4  0  4  0  0  0  0  0  4  0  4  4  0  0  0  0  4  4  0  4  4  0  0  4  0  0  0

generates a code of length 84 over Z8 who´s minimum homogenous weight is 68.

Homogenous weight enumerator: w(x)=1x^0+68x^68+28x^69+137x^70+92x^71+271x^72+342x^73+439x^74+648x^75+504x^76+1284x^77+674x^78+2126x^79+816x^80+3348x^81+812x^82+4454x^83+847x^84+4194x^85+833x^86+3532x^87+742x^88+2334x^89+671x^90+1124x^91+502x^92+632x^93+346x^94+262x^95+240x^96+120x^97+134x^98+46x^99+73x^100+6x^101+40x^102+4x^103+25x^104+8x^106+4x^108+2x^110+1x^112+2x^116

The gray image is a code over GF(2) with n=336, k=15 and d=136.
This code was found by Heurico 1.16 in 89 seconds.