My 87 fleetwood de elegance 5.1 with 140,000 miles and rebuilt 40,000 miles ago started popping through carb. took valve covers off front and left rocker is not moving at all. code 13 was showing which is oxegen sensor . all plugs were black carboned up. How do I get the push rod off or any ideas if this is the cam? Thanks bob redefbob@yahoo.com

Rocker arm not moving is not good. It sounds like camshaft lobe is gone...which means $$$$ The HT4100 is not the normal push rod V8 you will need a Factory Service Manual to properly repair it. You likely will need new cam,lifters, distributor gear, and related gaskets...timing set also highly recommended.

Thanks for the reply. Any possibility its the rod or lifter itself? I paln on pulling off the lifters. One person saildd just take off center nut/bolt. Any ideas?