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

generates a code of length 70 over Z8 who´s minimum homogenous weight is 68.

Homogenous weight enumerator: w(x)=1x^0+134x^68+32x^70+67x^72+12x^76+3x^80+6x^84+1x^88

The gray image is a code over GF(2) with n=280, k=8 and d=136.
This code was found by Heurico 1.16 in 9.86 seconds.