Riffraff Diesel Technical Knowledge Center
Riffraff Diesel 6637 Dry Washable Filter: BHAF Airflow Without the “Low Filtration” Tradeoff
Apr 9th 2026
If you’re doing the classic 7.3 Powerstroke 6637/BHAF intake mod, the filter is the whole point: big surface area, less restriction, built for work. The 6637 style has lived forever in the heavy
… read more
7.3 Powerstroke HPOP O-Ring Kit: Fix the Valley Leak the Smart Way
Apr 8th 2026
If you’ve got oil pooling in the 7.3 engine valley (under the fuel bowl/HPOP area), the HPOP is always on the suspect list—especially the rear/end plug and the high-pressure discharge fitt
… read more
7.3 Powerstroke HPOP Line Upgrade and JIC Conversion: Why it's a necessary upgrade
Apr 3rd 2026
If a 1999–2003 Ford 7.3 Powerstroke is leaving oil in the valley, one of the first suspects is the high-pressure oil (HPOP) hose and its STC quick-connect fittings. The upgraded Riffraff HPOP JI
… read more
Full Step By Step How To: 7.3L Billet Manifold Plenums
Mar 19th 2026
Parts Required:
Riffraff Diesel Billet Manifold Plenums 1994-2003, including:
(2) Billet plenums
(2) Viton o-rings
(1) Installation hardware packet
Recommended Parts:
Turbo/pedestal o-ring k
… read more
Fuel Rail Crossover (FRx) for the 6.0 Powerstroke: fixing the “deadhead” problem the clean way
Mar 19th 2026
Ford’s stock 6.0L fuel system is what’s known as a “deadhead” system. Fuel enters one side of the head and hits a dead end at the other end, which contributes to hotter fuel at
… read more






