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.
Power Driven Diesel Stage 2 CNC Ported 6BT 5.9L 12 Valve Cylinder Head
$1,950.00 – $2,300.00
New manufactured aftermarket 12v Cummins ported stage 2 cylinder head with reinforced ribs throughout, strengthened walls, thicker spring seats and deck surface. The gasket surface is freshly machined. This stage 2 ported head features a modern CNC port job that creates balanced flow across all 6 cylinders while providing large flow gains that combine with larger than stock valves to create a killer combination. The intake valve is upgraded to 1.87″ and the exhaust valve size was increased to 1.75″ (as big as we could fit into a standard 5.9L (4.015″) Cummins bore). On our flow bench test, we saw an average flow of 145% on the intake and 140% on the exhaust with peak valve lift numbers showing a 52% increase on the intake and a 50% increase on the exhaust. Our test recorded a maximum intake flow of 210 CFM and 215 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 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 large valve stage 2 cylinder heads really shine when combined with an aftermarket camshaft with larger than stock duration and lift!