The generator matrix

 1  0  1  1  1  1  1  1  1  1  1  1  1  1  1  0  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  7  1  1  1  1  1 21  1  1  1  1
 0  1  1 31 16 48  4 19  0 36 31 16 48  4 19  1 19 16 48 36  4  1  0 31 38 36  7 26  9 14 26  3  9  5 42 17 43 21 23 38 23  7 19 24 26 31 35 26 21  3  1 46 40 38 35 12  1  6  6 27  0
 0  0 35  0 35  7 35  7 42 14  7 42  0  0 42 14 21 28 14 21 42 14 21  7 35 21 21 42  7 35 21 35  7 28 28 28  0 35 42 28 42 28 35 14 21 28  0 35 42  0  0 14 14 28  0 28  7 42 21 35  0
 0  0  0  7 28 28 21 42  0 42  7 42 35 28 21 21 42 21 35 35 14  0 42  0 35 21  7 35 21  7 14 28 42 14 28 21  0 42 28 28  7 35  0 21 35  0 14 14 42 14 35 28 14  7 35 35 35 14 28 21  0

generates a code of length 61 over Z49 who´s minimum homogenous weight is 343.

Homogenous weight enumerator: w(x)=1x^0+564x^343+42x^345+2226x^349+2688x^350+798x^351+1176x^352+5712x^356+5850x^357+2016x^358+2394x^359+11844x^363+15018x^364+5922x^365+5922x^366+18186x^370+18192x^371+5670x^372+4872x^373+5250x^377+2820x^378+150x^385+156x^392+60x^399+66x^406+30x^413+24x^420

The gray image is a code over GF(7) with n=427, k=6 and d=343.
This code was found by Heurico 1.16 in 5.58 seconds.