How can I tell if I need to replace timing chain and all sprockets.where will the wear show.I'm rebuilding the Engine so this would be the time to repair it.If anyone has any thoughts please respond. Also I'm still trying to find the rubber part on the front engine limit stop.No one seems to know what it is.I can post a photo if interested.So far the oil use problem seems to be valve guides and seals.The pistons bore show about .30mm wear on top & about .02mm on bottom. They are very smooth and show no scratches of any kind.I will take to local auto machine shop to get opinion on what to replace and have them size and fit if necessary. Valves are burned bad and reflect low compression reading on 2 cylinders.Thank you for reading and all the interest.This is a great site.Gary H