I had a 99 WS6 T/A...they are not bullet proof. Mine was a good car...severely underrated power. Mine made 326 rwhp w/ a flowmaster muffler. The early ones...were suspected to burn oil and the pistons rings weren't suppse to seat well from the factory, and the valve springs sucked on the first one...People would float valves, but that is easily rememdied from a cam and valvetrain swap...but don't just go LS6....go big or go home.
I remember an article where a guy had longtubes, exhaust, lid, and a cam and made like 370 to the wheels. Then put on a TNT wet nitrous 10 shot and made something like 525 to the wheels and close to 600 lb/tq. Broke an axle on the way home. Just find one is good shape...many are ragged on, check for nitrous hookups etc.
It was a fun car (I had it in college) but I wouldn't buy another.
