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  X  0  1  1  X  0  1  1  X  1  1  0  X  1  0  1  1  1  1  1  X  0  1  0  1  1  1  X  1  1  0  0  2  1  1  X  2  1  1  2  1  1  1  X  X  1  0  1  1  1
 0  X  0 X+2  0 X+2  0 X+2  0 X+2  2 X+2  0 X+2  X  2 X+2  0  2  X X+2  X  0  0  2 X+2  X X+2  0  X  2  2  0 X+2 X+2  X X+2  0 X+2  X  0 X+2 X+2  X X+2  X X+2 X+2  X  X  0  0  X X+2 X+2  X X+2  X X+2 X+2  X X+2  X X+2  X  X  X  0  X X+2  0  X X+2  X  0  X  2 X+2 X+2 X+2  X X+2 X+2  2
 0  0  2  0  0  0  0  0  0  0  2  0  2  0  0  2  2  0  0  2  2  2  0  2  2  0  0  2  2  2  2  0  0  0  2  0  2  0  2  0  2  2  0  2  2  0  2  0  0  0  2  0  0  0  0  0  0  0  2  2  2  2  2  2  2  0  0  2  0  0  2  2  0  0  0  2  2  2  0  2  0  0  2  2
 0  0  0  2  0  0  0  0  0  0  0  2  0  0  2  0  2  0  0  2  0  2  2  2  2  0  2  2  2  0  2  2  0  0  0  2  0  0  2  0  2  2  0  2  0  2  0  2  2  2  0  0  0  0  2  0  0  2  2  2  0  0  2  0  0  2  0  2  2  2  0  2  2  0  2  2  2  0  2  2  2  2  2  2
 0  0  0  0  2  0  0  0  0  0  0  0  2  0  0  0  0  2  2  0  0  0  2  2  0  0  0  0  2  0  2  0  0  2  0  2  2  2  2  0  0  2  0  0  2  2  2  2  0  0  0  2  2  2  2  0  2  0  2  2  2  2  0  2  0  2  2  2  0  0  2  2  2  2  0  0  0  2  0  0  2  0  2  2
 0  0  0  0  0  2  0  0  0  2  0  2  0  2  0  0  2  2  2  2  0  0  2  0  2  0  0  2  2  2  0  2  0  0  2  0  2  2  2  2  0  0  0  0  0  0  2  2  2  0  2  0  0  0  2  0  2  2  2  0  0  2  0  0  0  0  2  2  0  2  0  2  0  0  0  2  2  2  0  2  2  0  0  0
 0  0  0  0  0  0  2  0  0  0  0  0  2  0  0  2  2  2  0  2  2  2  2  0  2  2  2  0  0  0  2  2  0  2  2  2  2  0  2  2  0  2  2  0  0  0  0  0  2  2  0  2  0  2  0  0  0  0  2  0  0  0  0  2  0  0  2  2  2  0  0  0  2  0  2  0  2  2  0  2  0  2  2  0
 0  0  0  0  0  0  0  2  0  2  0  0  0  0  2  0  2  2  2  2  2  0  0  2  0  0  2  0  0  2  2  0  2  2  0  2  2  0  0  0  0  0  2  0  0  2  0  0  0  2  0  2  2  0  2  0  2  2  0  0  0  2  2  2  2  2  0  2  0  2  2  0  0  2  2  0  2  0  0  0  2  2  2  0
 0  0  0  0  0  0  0  0  2  0  2  2  2  2  2  2  2  0  0  0  0  0  2  0  2  2  0  2  0  0  0  0  2  0  0  0  0  0  2  2  2  0  2  2  0  0  2  2  2  2  0  2  0  0  2  0  2  0  0  0  2  2  0  2  2  2  0  2  2  2  2  2  0  2  0  0  0  2  0  0  0  0  2  2

generates a code of length 84 over Z4[X]/(X^2+2,2X) who´s minimum homogenous weight is 73.

Homogenous weight enumerator: w(x)=1x^0+18x^73+57x^74+66x^75+130x^76+62x^77+238x^78+108x^79+354x^80+142x^81+500x^82+108x^83+604x^84+148x^85+481x^86+112x^87+328x^88+102x^89+196x^90+98x^91+81x^92+30x^93+38x^94+20x^95+17x^96+10x^97+12x^98+15x^100+7x^102+4x^104+3x^106+1x^108+3x^110+1x^116+1x^126

The gray image is a code over GF(2) with n=336, k=12 and d=146.
This code was found by Heurico 1.16 in 46.9 seconds.