G.M front pads

does anyone know what the brand name of the original equip front pads are that g.m uses on their 2005 impala's,I just took off the fr rotors and pads after 58 000km's and replaced them with the napa fr rotors $100 bucks a piece and napa's ceramic pads $80 bucks a set,after 500 km's now the brake is good but is not near as good or touchy as the original,any one know if they still use rabestas pads,the orignal pads where the best brake verses what I have on now,thinking of switching pads again if anyone knows what the brand name of original pads are,anyone know?

18045380 is the GM part number for front pads. I don't know the brand, sorry.
18023377 is the GM number for the rear pads.