Will changing lid add power
Better clean it just to make sure.
Just a tip, after you soak it in cleaner, then wash it till it's clean, go stick it on your A/C condensing unit outside your house. The warm little breeze blowing out the top will dry it out in no time.

Also, when re-oiling it, just spray the side that faces the radiator when installed in the car, it will make it's way farther into the fibers as the car is running. Don't use too much either.


GMHighTech mag did a comparioson and they were all within about 2 hp from each other and all added around 10 hp to the wheels. 