This part may save your engine!! The MMR cylinder head oiling modification ( oil balance lines ) joins the left and right cylinder head together with the MMR Balance tube and fittings and balances bank to bank pressure and flow. In the event that the VERY small factory pressure orifice is clogged the head will continue to receive oil due to the MMR balance tube. MMR has seen hundreds of cylinder heads ruined because of oil starvation, this simple, easy to install mod will guarantee that your cylinder heads always remain lubricated along with perfectly balanced pressure. THIS IS A MUST FOR ALL PERFORMANCE APPLICATIONS!! MMR also suggests the head cooling mod (HCM) for all performance applications (PN#455478) NOTE: While we have seen some copies of the MMR product it should be noted that those kits using 2 hoses to join all of the lifter bores together are 100% unnecessary, they add cost, installation complexity, increased points for failure and leaking, increased weight and redundancy, this is because the lifter bores are already joined at the front of the cylinder head via a machined tunnel in the casting making a second hose completely useless. Includes: Black Anodized MMR Cylinder head Fittings Black Teflon Motorsports Hose (high pressure and temperature)Learn More