The generator matrix

 1  0  1  1  1  1  1  1  1  1  1  1  1  1  1  X  1  1  1  1  1  1  1 3X  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 2X  1  1 6X  1  1  1  1  1  1  1 4X
 0  1 5X+1  3 5X+2  6 5X+4  5  X 4X+1 X+3 4X+2 X+6 4X+4 X+5  1 3X 6X+1 3X+3 6X+2 3X+6 6X+4 3X+5  1 2X 5X+1 2X+3 2X+2 2X+6 2X+4 4X+1 2X+5 2X+1 6X 6X+3 3X+2 6X+6 3X+4 6X+5 4X 4X+3 3X+1 X+2 4X+6 X+4 4X+5 5X 5X+3  2 X+1 5X+6  4 5X+5  1  0  1  3 5X+2  1  X X+3 4X+2 3X 6X+1 3X+3 6X+2  1

generates a code of length 67 over Z7[X]/(X^2) who´s minimum homogenous weight is 398.

Homogenous weight enumerator: w(x)=1x^0+504x^398+24x^399+252x^401+882x^402+672x^405+42x^408+18x^420+6x^427

The gray image is a linear code over GF(7) with n=469, k=4 and d=398.
This code was found by Heurico 1.16 in 1.56 seconds.