Having just done it, one tooth is a WHOLE LOT of rotation. We've had this discussion before, when somebody wanted to take a pitch out of the chain to tighten it up ... an entire link's worth is a whole lot of distance (many times the amounts we are talking for total wear amounts).
-- our wear amount from new chain to dead chain is worth maybe a pins worth of wear distance (little more than 1/8")
-- wear on the guides counts for about as much as chain wear does towards giving "too much slack" to a stock cam chain adjuster's original travel.
NO ONE has ever worn through the plastic on a set of guides yet, that I remember hearing about anyway. Maybe I'll get to be the very first one.
Cracks, yes they all develop cracks during the first run at their jobs and some edge stuff begins breaking off during the second life time -- but no gross wear throughs noted so far. Guide channels are not immortal any more than the silly chains are.
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And Bill, mine is going to be Rotella oil impregnated pressure treated hard wood -- that's extra special.
And my hardwood rod was cut from a American Magic Hickory Tree, so I will have magic Rotella impregnated Hickory sparkles right in my engine acting magically all the time -- better than your old red pixie dust magic any day.
.... and it isn't going anywhere until one of you jokers finds a set of valve covers and a big rubber cam end plug thingie so I can finish putting it together.