The generator matrix

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

generates a code of length 71 over Z8 who´s minimum homogenous weight is 70.

Homogenous weight enumerator: w(x)=1x^0+12x^70+90x^71+13x^72+2x^74+4x^75+2x^76+1x^78+2x^79+1x^86

The gray image is a code over GF(2) with n=284, k=7 and d=140.
This code was found by Heurico 1.16 in 0.114 seconds.