Stock trailing arms + bags: notch necessary?

[Jet Blue 68]

Hi Everyone!

I've got a 68 SWB I am needing help with. Right now everything is stock, 6 lugs and drums. An upcoming disc brake and rearend change make it a good time to go ahead and bag it also. I've took a few measurements and have a couple questions... (I'll try to get some pics sometime later this week.) I plan to bag my truck very basic, and have been very skiddish of notching, so after obsessing and crawling under the truck with a tape measure here's what I've came up with.
From my rear trailing arms to my frame I have appx. 10-11 inches of travel. Which is obviously also the height of my rear coil springs... From research a compressed bag is about 3 inches, so that leaves 7-8 inches of lift or drop. My rearend is 6 1/2 - 7 inches from the frame (bottomed out)...
I don't really plan on riding around "aired out" all the time, probably only when parked, so other than an extra 1-2 inchs of space above the axle- what do I gain? Does it really allow it to sit 2-3 inches lower? I know I'm probably missing something here, but it's hard to argue with a measuring tape and yourself- ya know?From what I can tell, bottomed out = bottomed out. Trailing arm vs. frame is no different from frame vs. axle... or is it?
I'm sure this is a very common setup (staying mostly stock), so I know someone with some experience can help. I'm not ashamed to say and have never bagged a vehicle. Also if anybody out there is running a no notch airbag setup with some pics they could throw this way that would be cool too... I'm talkin side profiles, frame/rearend/bag set up pic, anything ya'll think might help me get started. I'm trying to see how low I can get without "major" modification. Thanks!