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

generates a code of length 51 over GR(64,4) who´s minimum homogenous weight is 328.

Homogenous weight enumerator: w(x)=1x^0+105x^328+756x^336+693x^344+3584x^350+630x^352+25088x^358+504x^360+469x^368+448x^376+203x^384+203x^392+77x^400+7x^408

The gray image is a code over GF(8) with n=408, k=5 and d=328.
This code was found by Heurico 1.16 in 0.519 seconds.