You probably read my posts abotu that here and/or possibly on the 300M ezBoard forum.
NAPA part number is 86777. It is a Raybestos re-boxed as NAPA's in-house Unite Brake brand (both are divisions of Dana). Don't let the counter guy look up your car in the computer - their listings are incorrect - make them get the part number I gave you. $47 each.
This is the PHP/PHG (Performance Handling Package/Performance Handling Group) rotor. For any 2nd Gen. LH car, it is a plug-n-play replacement for your factory rotor *AS LONG AS* your car came with wheels larger than 15" from the factory. (FYI, rotors for 15" wheels are Ø282mm; rotors for large wheels (PHP/PHG and non-PHP/PHG) are Ø297mm).
Thickness is the same for all front LH rotors. The difference in PHP/PHG and non-PHP/PHG is in the venting. Non-PHP/PHG rotors are inside-vented (pull air form engine side). PHP/PHG are outside-vented - pull air from curbside.
If your car came with 15" wheels from the factory, you can convert to either of the larger rotors (PHP/PHG or non-PHP/PHG) by replacing the steering knuckles (also called spindles), and using your same calipers and pads - oh - and getting 16" or larger wheels. I did this on my Concorde - works great (I also had my the new PHP/PHG rotors cyrogenically treated - but that is another topic). I got the spindles from a salvage yard for $50 each.
All above comments apply to front brakes only. Rear brake components are identical for all 2nd Gen. LH cars.
BTW - when I converted from the smaller (and inside-vented) rotor to the PHP (larger and outside-vented) rotor, one big difference I noticed immediately was no delay from application of brakes to braking effect that I had experienced with the original rotors and had been a concern of mine. Apparently the venting made the difference in keeping the rain off the rotors.
Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")