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  2  1  1  2  1  1
 0  2  0  0  0  2  2  2 2a  0  2 2a 2a 2a 2a  2 2a 2a^2+2a+2 2a^2 2a+2 2a^2+2a 2a 2a^2 2a^2+2 2a^2+2  2 2a^2+2a+2 2a^2+2a  2  0  0
 0  0  2  0  0 2a^2+2 2a^2+2a+2 2a^2+2a 2a^2+2a  2 2a+2 2a^2+2  0  2 2a^2+2a+2 2a^2 2a 2a^2+2 2a^2 2a+2  2  2  2 2a+2 2a^2+2a 2a+2 2a 2a^2 2a  2  0
 0  0  0  2  0  2 2a^2+2a+2 2a 2a+2 2a^2 2a^2+2  0 2a^2+2a+2  2 2a 2a^2+2a 2a^2+2a 2a^2+2a 2a^2+2a  0 2a^2+2a+2 2a^2+2a+2 2a 2a^2+2a  0 2a^2+2a+2 2a^2 2a^2 2a 2a^2+2a  0
 0  0  0  0  2 2a^2+2 2a+2 2a 2a^2+2a+2 2a 2a^2 2a^2 2a+2  0 2a  0 2a^2 2a^2+2a 2a^2+2a+2  2 2a^2 2a^2+2 2a^2+2 2a^2+2a+2 2a^2+2a  2 2a^2+2a 2a^2 2a^2+2a  0  0

generates a code of length 31 over GR(64,4) who´s minimum homogenous weight is 176.

Homogenous weight enumerator: w(x)=1x^0+217x^176+973x^184+2338x^192+3227x^200+3584x^203+4571x^208+50176x^211+6097x^216+175616x^219+6993x^224+5369x^232+2520x^240+462x^248

The gray image is a code over GF(8) with n=248, k=6 and d=176.
This code was found by Heurico 1.16 in 16.4 seconds.