79 W-150's, 203 case does definitely have a chain and as all chains, will stretch. My original truck has 110,xxx miles on it and is stretched as indicated by a resounding "clunk" when putting in drive or reverse...no other ill effects to date.
Here's a pic of the chain/case taken during the resto. on my Warlock a couple of years ago: BTW it had 120,xxx on it, same thing "clunk", but no other problems... We were able to find a chain for it at that time.

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Last edited by 4x4 Roundup; 12/25/19 08:06 PM.
WANTED-- DEAD or ALIVE:
'70 Duster--- VS29H0B274908-----UPDATE---ENGINE BLOCK FOUND---Still looking for the B-5 car.
'79 Power Wagon W14JE9S137761 or 763