reinstall Lion OX setup assist/time machine.

I Need to do an erases and install of snow Leopard which I can do as indicated in Article HT3910. My question is 6 months ago I updated to Lion but only have the original Snow Leopard install disk, Will I need to update back to Lion before I can run setup assist and restore all my files from my Time machine back up. or will the time machine backup made with Lion run on Snow Leopard.