I am installing a sissybar w/back rest on my 08 SG do I need to have a rack for my Kuryakyn grand tour pack or can I just flip it around and use my seat as a base? I dont want to pay $200-$300 for a rack

 

You can just flip it around and use it on your seat. When I had that style of bike I preferred it on the set if I didn't have a passenger. It may double as a backrest for you if you add something else to the front. I used a bedroll on a long trip and it was perfect with the Kury bag on the seat with a bedroll bungee corded to the front of it.