The generator matrix

 1  0  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  0  1  1  1  1  1  1  1  1  1  1  1  0  1  1  1  1  1  2  1  1  1  1  1  1  1  1  1  1  2  1  1  1  1
 0  1  1  a 3a^2+2 2a^2+3a+1 a^2+3a a^2+3a+3 3a^2+2a+3  a 3a^2+2  0 2a^2+3 a^2+3a+3 a^2+3a 3a^2+2a+3 2a^2+3a+1  1 2a^2+3 a^2+3a+3 2a^2+3a+1  a 3a^2+2 a+2 a^2+3a+1 a^2+3a 2a^2+3a+3 3a+1 2a^2+3  1 3a^2+2a+3 a^2+a+3 3a^2+a+3 3a^2+2a+2 3a  1 2a^2+a+1 2a^2+2a+1  0 2a+1 3a^2+2a+2  2 a^2+a a^2 a^2+a 3a  1 3a^2+2a+2 3a^2+3a 2a  0
 0  0 2a^2+2  0  2  2 2a+2  2 2a^2 2a+2 2a^2+2 2a^2 2a^2  0  0 2a^2 2a^2+2  2  2 2a 2a+2 2a^2+2a 2a+2 2a^2+2  0 2a^2+2a+2 2a^2+2a 2a+2 2a^2+2a 2a^2 2a^2+2a  2 2a^2  0 2a 2a^2 2a+2 2a^2+2a  2 2a^2 2a^2+2 2a^2+2a  0 2a 2a^2+2a  2 2a^2+2a 2a+2 2a^2+2 2a+2  0
 0  0  0  2 2a^2+2 2a^2+2a+2 2a+2 2a^2 2a^2+2a+2 2a^2+2 2a^2+2 2a^2+2a 2a 2a^2 2a^2+2a+2  0 2a^2+2a 2a^2+2a+2 2a 2a+2  0 2a^2+2a  2 2a+2 2a 2a^2+2a+2  2 2a^2 2a+2  0 2a^2+2 2a^2+2a 2a^2+2 2a^2 2a^2+2  2 2a^2+2a+2  2 2a+2 2a^2+2a+2 2a+2 2a 2a+2 2a^2 2a^2+2a 2a^2+2a+2 2a^2+2 2a^2+2 2a  0 2a

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

Homogenous weight enumerator: w(x)=1x^0+147x^328+168x^331+56x^332+742x^336+504x^338+6160x^339+1624x^340+1869x^344+2968x^346+20832x^347+4200x^348+8897x^352+10472x^354+68208x^355+11592x^356+19754x^360+14728x^362+76664x^363+11200x^364+413x^368+336x^376+378x^384+175x^392+49x^400+7x^408

The gray image is a code over GF(8) with n=408, k=6 and d=328.
This code was found by Heurico 1.16 in 11.9 seconds.