Looser converter will help a lot.
try the total timing at 38 if it don't ping that will help raise the idle advance.
maybe a lighter set of advance springs are in order too to get the idle advance "initial" a little higher.

One easy test is to advance it at idle say ten degrees and set the idle and see if you can get better idle there if you can turn back total and then lighter advance springs. (just a idle test no road test as your total will be 44) more idle advance will let you close the carb off to where the idle circit works better as well.