Are you looking for the same cylinder heads used on the MMR GenX crate engines and by the team MMR Pro Mods? Look no further: MMR Race Ported Cylinder heads (pr.) are the best and fastest in the business and the only heads to win championships in multiple categories from 2011-2018 and are the only cylinder heads to run in the 5-second zone and hold the current world record for the Ford Coyote engine!! Dyno tested and Racetrack Proven – PERIOD These are Brand New GT350 Cylinder Heads that have received an additional and professional CNC Port Job Picking up flow higher than ANY aftermarket head currently available. Available with MMR’s drydeck welded drydeck process. Strongest and most advanced design ever! Fully Ported Intake Port Fully Ported Exhaust Port Combustion Chamber re-profiled to 59cc (spark plug unshrouded) Fully assembled with Valves and Springs (see options below) Direct bolt-on for ALL 2011-2017 and 2018-2020 GT350 & GT500 5.0 Coyote Engines including F150 and Australian Models.