The generator matrix

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

generates a code of length 7 over GR(64,4) who´s minimum homogenous weight is 40.

Homogenous weight enumerator: w(x)=1x^0+147x^40+3136x^42+147x^48+7168x^49+21952x^50+217x^56

The gray image is a code over GF(8) with n=56, k=5 and d=40.
This code was found by Heurico 1.16 in 0.00787 seconds.