M30 Rocker Arm Lock Set ship-solo This head allows the option

This head allows the option of original (good used condition) OE BMW dual valve springs

On factory M30 cylinder heads

Set of 6 NGK V-Power spark plugs

This is a stock replacement for the M20B25 engine

Replaces BMW part number 11111735525

M30 Rocker Arm Lock Set ship-solo This head allows the optionOn factory M30 cylinder heads, the rockers are held in position by a spring. At high RPMs, that spring may allow the rocker to move in relation to the valve stem (sometimes enough to walk off the valve stem) which quickly results in a broken rocker arm. With rocker arm locks, you eliminate the spring and positively locate the rocker arm. Locks also make head assembly simpler than with thrust springs. We use these on all of our performance engines and