The generator matrix

 1  0  1  1  1  1  1  1  1  1  1  0  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  7  1  1  1  7  1  1  1  1 21 21 42  1  1
 0  1  1 31 16 48  4 19  0 36 31  1 16 19 48 36  4  7 38 26  9  9  7 26 21  5 30 30 21 29 29 42 12  2 12 22  8 22  5  6 46  1 38  6 46  1 17 25 34 34  1  1  1 39 39
 0  0 35 21 42  7 14 21  7 28 14  7 35  0  0 42 28 14 42 28  7 21 42 35 21 14 28  0 35  7 14 28  0 14 28 42 35 28 21 35  0 42 35 21 42 14  0 21 14 42 21 35 28 28 14

generates a code of length 55 over Z49 who´s minimum homogenous weight is 321.

Homogenous weight enumerator: w(x)=1x^0+420x^321+768x^322+3444x^323+2100x^324+630x^328+600x^329+1344x^330+504x^331+1008x^335+972x^336+3444x^337+1512x^338+6x^343+42x^350+12x^357

The gray image is a code over GF(7) with n=385, k=5 and d=321.
This code was found by Heurico 1.16 in 3.61 seconds.