The 1050 105 you have is better than the Tourney. If you are planning on running larger cogs (like a 32), I would highly recommend a Deore XT/LX or even an Exage 500LX (M500) c. early 90s as a replacement. They can handle the larger cogs (long cage) and you would have no issues with chain wrap. And they are 7sp index and the quality is equal or better than your 105.