Need 2 window channel balances; and 2 sash support

Hello! I think you could use our 18-159P top sash guide in place of your guides. These are usually used with the S390-27 channel balance. This comes with the 19-002 top and 15-001 bottom, so as long as those match you should be okay. See if our balance is compatible with yours. In order to determine the proper stamp option, you will have to weigh your sash on a scale and refer to the chart we show on the S390-27 store page.