Assuming you got the IDs from NEI, you should not have to shift them. If the IDs are right, this should work:
recipe.remove(<8790>);
recipes.addShaped(<8790>, [[<14300:16>,<1225>,<14300:16>],[<903:3>,<8786>,<903:3>] ,[<14300:16>,<903:3>,<14300:16>]]);
recipes.addShaped(<8790>...