4.6L / 5.4L 2V NPI N/A Camshafts

4.6L / 5.4L 2V NPI N/A Cams

NPI heads have different needs than PI heads so we offer NPI specific cams. NPI heads have much more piston to valve clearance than a PI engine, this allows more freedom in camshaft design. They have more restricted exhaust ports so the exhaust duration is made longer to compensate. The .525" intake lift cams will work on stock NPI heads, the .550" lift version will need raised retainers on the intake valves or other modification to work. .500" exhaust lift is used for Stage 1 and 2 as the stock exhaust port stalls at .400" lift.

All NPI NA cams are designed to use the stock NPI valve springs up to 6500RPM, above that upgraded valve springs are highly recommended.

These NPI specific cams will NOT work in a stock 4.6 PI engine as they will bend the intake valves due to their aggressive intake centerline location!