I am running 98-2002 F body disc on my 9" in a first gen camaro. My axle guy welded a flange on the axle that directly adapted it to allow the GM housing to bolt on. I am running C5 rear rims with no adapters.
Totally budget and looks/works great.
Here is a pic of the first rough fit of the axle to the car.
NOTE-the LS1 4th gen brakes are 12" and they use the mini drum brake for the parking brake system.
