After looking online, I've had no luck finding a place to buy Donaldson filters for a decent price, does anyone know where they can be bought for a fair price? My co worker just picked up a few P550794 oil filters for his 4.8 Chevy (P550794 crosses to ACDelco PF48/PF48E) He bought 6 at $4.61 each, but shipping was $17 so he wont be buying them again unless they can be had for cheaper. They are built like a tank, very heavy, and the louvers in the center tube are well formed and open. It has a nitrile anti drain back valve but seems to be well made. Does Donaldson make most of their filters in house or do they source some to an outside party? I can get Baldwins from a local distributor for a great price, they have a large selection in stock at all times. Which would you pick between Baldwin and Donaldson? Either one seems built very well.