The generator matrix

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

generates a code of length 69 over GR(64,4) who´s minimum homogenous weight is 467.

Homogenous weight enumerator: w(x)=1x^0+8064x^467+12152x^468+1792x^469+336x^471+28x^472+30688x^475+29792x^476+4928x^477+1120x^479+231x^480+39872x^483+37016x^484+2688x^485+2128x^487+245x^488+46816x^491+39312x^492+4928x^493+7x^520

The gray image is a code over GF(8) with n=552, k=6 and d=467.
This code was found by Heurico 1.16 in 13.9 seconds.