Need to change the plugs - I assume change the wires as well? I figure I can probably do this myself although its been awhile.

Transmission - I did a "fluid change" at 50k. Should I do the same and avoid the dreaded "flush"?

Rear Differential - I have a 2wd so do I need to ever change this fluid? I would imagine this is more critical to a transfer case with 4wd but not sure. thoughts?

Thanks in advance

1ags hooked me up with a 100k service on my 4x4 truck. Did the following :

Front Diff
Rear Diff
Transfer Case
Trans Service (drain and fill)
Spark Plugs
Brake Fluid
Belt Change
Lube all Zerks

Even though you are 2wd I'd still do the rear diff. I don't think I'd replace the spark plug wires.

Don't forget to check your lower ball joints. Tahoes and Suburbans are notorious for ball joint wear.

I'd do the wires while you're there, they're fairly cheap.