Here is a picture of what not to do to get the needed rocker-to-retainer clearance. Because Chrysler used net-shape-casting technology, there's no extra beef and the integrity of every surface is essential to overall rocker arm strength. Grinding a groove to provide clearance (pen points)-then adding a stiffer spring-will lead to a fracture. A stock Chrysler rocker is shown for comparison on the left. Also note the size difference between the 0.900-inch Chrysler retainer and the 1.155-inch titanium replacement (right) that's required to match the up-sized spring diameter.