Power Driven Diesel Stage 1 CNC Ported 6BT 5.9L 12 Valve Cylinder Head for 89-98 Cummins

New manufactured aftermarket 12v Cummins ported stage 1 cylinder head with reinforced ribs throughout, strengthened walls, thicker spring seats, and deck surface.

The gasket surface is freshly machined.

This stage 1 ported head features a modern CNC port job that creates balanced flow across all 6 cylinders while providing large flow gains with the stock-sized valves.

On our flow bench test, we saw an average flow of 137% on the intake and 134% on the exhaust with peak valve lift numbers showing a 48% increase on the intake and a 46% increase on the exhaust.

Our test recorded a maximum intake flow of 195 CFM and 203 CFM exhaust flow at 28″.

Keep in mind that flow benches vary so it’s likely that some test stands will show slightly more and some will show slightly less flow.

In real-world testing, the higher flow from this ported head slightly raised engine efficiency and peak power performance with resulting lower boost pressure and lower EGT readings compared to the stock cylinder head.

Although a bigger than stock camshaft is not required, these ported cylinder heads really shine when combined with an aftermarket camshaft with larger than stock duration and lift!

Head is freshly surfaced and assembled with Cummins OEM style valves, PDD 60lb Valve Springs, and PDD Chromoly Retainers.

Includes:
6 – Intake Valve
6 – Exhaust Valve
12 – Top Hat Style Valve Stem Seals
12 – PDD 60lb Valve Springs
12 – PDD Chromoly Valve Spring Retainers with Locks (for use up to 4,200 rpm with small to moderate cams)

• If you own an 88-91.5 non-intercooled Cummins, you will need to upgrade to injectors with 7mm nozzles in order to use this cylinder head.