Good question. Don't really remember
I went to
http://www.f-body.org years ago and bought from a couple of the shops advertised there, but because of the restrictions on allowed mods for autox stock classes I only got koni single-adjustable shocks, air filter, plugs, wires, and brake pads.
For OEM parts I usually end up buying from GMPartsDirect.com, and I eventually switched back to genuine GM-distributed OEM brake pads because they seemed to last a long time even when racing autox, without any squealing with minimal dusting. I tried the GM durastop pads but they dusted badly and were downright hazardous in the rain since they'd float for a second then grab one at a time. I think slotted or drilled rotors are pretty much required for durastop pads to be safe, but autox doesn't allow that in stock classes so no durastops for me.
f-body.org has had some ups and downs and right now they seem to be operating, but it's not as robust of a site as it used to be. Still, it's probably a good place to start looking.
