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

generates a code of length 79 over Z7[X]/(X^2) who´s minimum homogenous weight is 467.

Homogenous weight enumerator: w(x)=1x^0+882x^467+186x^469+294x^474+96x^476+882x^481+12x^483+12x^490+24x^497+12x^504

The gray image is a linear code over GF(7) with n=553, k=4 and d=467.
This code was found by Heurico 1.16 in 3.3 seconds.