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

generates a code of length 72 over Z8 who´s minimum homogenous weight is 68.

Homogenous weight enumerator: w(x)=1x^0+16x^68+220x^72+16x^76+1x^80+2x^104

The gray image is a code over GF(2) with n=288, k=8 and d=136.
This code was found by Heurico 1.16 in 0.116 seconds.