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

generates a code of length 74 over GR(64,4) who´s minimum homogenous weight is 488.

Homogenous weight enumerator: w(x)=1x^0+154x^488+735x^496+1232x^504+6825x^512+22463x^520+406x^528+294x^536+189x^544+175x^552+133x^560+84x^568+63x^576+14x^584

The gray image is a code over GF(8) with n=592, k=5 and d=488.
This code was found by Heurico 1.16 in 0.818 seconds.