Thanks for reminding me of no front cover, duh! I'm getting my engines mixed up since started dabbling in bricks too.
The chain guides on an om617 don't near as much as the v8s. The I5 engine has a simple loop for a chain path so there isn't much work for the guides if the tensioner is working. The v8 makes the chain change directions four times (even more on the new 3 valve engines and the older 4 valvers) so the guides take more abuse.
The chain crimper is pretty easy to use, the manual explains it pretty well. Actually the M103 engine manual explains it well, the om617 manual left me wondering so I checked the other engine manual. Anyway, if you drop the chain you get to do the "fun with magnets" trick or try your luck with a hooked tool until you get lucky.