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 X^3  1  1  1  1  1  1  1  1 X^3  1  0  1  X  1  1
 0  X  0 X^2+X X^2 X^3+X^2+X X^3+X^2  X X^2 X^2+X X^3 X^3+X X^3 X^3+X^2+X X^3+X^2  X X^3+X^2+X  0 X^3+X X^3+X^2 X^3 X^3+X^2+X  X X^2 X^3+X^2 X^2+X X^3  X  X  0 X^2 X^2+X X^2+X  0 X^2+X X^2  0 X^2  X X^3+X X^2+X X^2+X  0 X^2  0 X^2 X^3+X  X  X X^3+X  0 X^2 X^3+X X^3 X^2+X X^3+X^2 X^3+X^2  X X^3+X^2+X  0 X^3 X^3+X^2 X^2 X^2+X X^3 X^3+X^2+X X^2+X X^3+X^2+X X^3+X^2+X X^2+X X^3+X^2 X^2 X^2 X^2 X^3+X  X X^2 X^3+X^2+X  0 X^2+X
 0  0 X^3+X^2  0 X^2 X^2  0 X^2 X^3+X^2  0 X^2  0  0 X^3+X^2  0 X^3+X^2 X^3 X^3 X^3 X^3 X^2 X^3+X^2 X^3+X^2 X^2 X^3+X^2 X^2 X^3+X^2 X^2 X^3 X^3 X^3 X^3  0  0 X^3+X^2 X^2 X^3+X^2  0 X^2  0 X^3 X^3+X^2  0 X^2 X^3+X^2  0 X^3+X^2 X^3 X^2 X^3 X^3 X^3+X^2 X^3+X^2 X^3 X^2 X^3 X^3+X^2  0  0 X^2 X^2 X^3 X^3 X^3  0 X^2  0  0 X^2 X^3+X^2 X^3+X^2 X^3+X^2  0 X^2 X^2  0 X^3 X^2 X^3+X^2  0
 0  0  0 X^3  0  0 X^3 X^3 X^3 X^3 X^3  0 X^3  0  0 X^3 X^3 X^3  0  0  0  0 X^3 X^3  0  0 X^3 X^3  0  0 X^3 X^3  0  0 X^3 X^3 X^3  0  0 X^3  0 X^3 X^3  0  0 X^3  0 X^3  0 X^3 X^3  0  0  0 X^3 X^3 X^3 X^3  0  0 X^3  0 X^3  0  0 X^3  0 X^3 X^3  0  0  0 X^3  0  0 X^3  0  0  0 X^3
 0  0  0  0 X^3  0  0  0  0 X^3 X^3 X^3 X^3 X^3 X^3 X^3 X^3 X^3 X^3 X^3  0  0  0  0 X^3 X^3 X^3 X^3  0  0  0  0  0 X^3  0 X^3  0  0  0  0 X^3 X^3  0  0 X^3 X^3  0  0 X^3 X^3  0  0 X^3 X^3  0 X^3 X^3 X^3 X^3 X^3  0  0 X^3  0  0 X^3 X^3  0  0 X^3  0 X^3  0  0  0  0 X^3  0  0 X^3

generates a code of length 80 over Z2[X]/(X^4) who´s minimum homogenous weight is 76.

Homogenous weight enumerator: w(x)=1x^0+180x^76+80x^77+296x^78+384x^79+377x^80+272x^81+184x^82+32x^83+148x^84+64x^86+29x^88+1x^152

The gray image is a linear code over GF(2) with n=640, k=11 and d=304.
This code was found by Heurico 1.16 in 38 seconds.