BajaSurfRig
Active member
I just recently purchase a 96 F350 CCLB 7.3 4x4 and it came with a Napa 6637 filter. I find myself in some pretty dusty conditions on occasion and am curious what the best filter out there for filtering in those conditions with a 7.3 is (I don't want to dust my turbo or engine). I would like to make the AIS severe duty filter (for the late 99 to 03) fit but don't really want to do the trimming that is required for it. I just ordered a donaldson 6637 along with a Riff Raff pre filter cover for an upcoming trip. My fear is that there is no box around the filter still and that one bad splash through a creek crossing could do some damage. What do you guys recommend?