Hello, I have a 2002 Envoy which I lifted myself. I have seen people with the Saab 9-7x using the same lift as a TB and Envoy so that shouldnt be a problem for your Olds.
There are not a whole lot of options as fas as lifting a GMT-360 platform. From the knowledge I have gained at this site, the most you can lift your suspension is about 3 inches. There are also body lifts available, but I have noticed that the frame sits a little lower then the body, and a body lift would only make that difference greater and more noticible.
I went with a 3 Inch front, 2 inch rear suspension spacer kit. AKA Lift kit, AKA Leveling Kit, or whatever you want to call it. It bolted directly to the top of the front strut assembly and seated on top of the spring in the rear. The difference is astonishing and with my new clearance, along with 1.5in wheel spacers, I was able to put 32.5in tires. It sits about 5 inches higher then it did stock, and it still rides great.
Others use rear springs out of a Z71 Tahoe instead of spacers, and from pics they also look awesome. I have even seen others using springs out of a Toyota pick up but unless your in the mood to fabricate them so they seat properly, I do not recomend it.
Hope this helps, PLEASE post pics regarding your progress, I dont thnk I have ever seen a lifted Oldsmobile brefore