Originally posted by ILUVMILS
There's a service bulletin( it's a few years old )concerning timing chain stretch on your 87' 6cyl. 603. The chain should be replaced at 5 degrees of stretch. If it stretches 10 degrees you could have some major problems! This forum has loads of info on 116/117 timing chain issues, but believe me, you ain't seen nothin' until you've seen a 603 chain break!!!. It breaks the camshaft into six pieces, bends most of the valves, and due to valve train geometry, often damages the cylinder head beyond repair. I've also seen the injection pump gear, front engine cover and chain oiling nozzle damaged as well. The good news is that it's easy to check the amount of stretch. Just remove the boost cross-over pipe and valve cover and line up the marks. The amount of stretch can be read on the front balancer.
What would running a car with 10 degrees advance do to the engine? Is it possible there would be no damage?