85TrailToy said:
A friend of mine has an '87 with about 215k on it. Factory timing set. Now that's living on borrowed time!
Is it a 22re? The 22r with double row chain could easily go that far without problems, but if it's EFI, then WHOA!
I don't know firsthand, but I was told by techs at DOA and LC that in general, plastic guides are preferred. Metal guides should only be used if you keep track of maintenance and change your chain every 75k. The metal guides will protect your timing cover from getting chewed. It's harder to tell if the chain is worn, though, so it's possible to have the chain wear way too much and break before you can detect a problem.
My original factory guides were broken, but didn't seem very worn. I think when the tensioner ran out of travel, the chain started slapping and just broke them.