Herte's a different take on double roller timing chains:
Back in 1972 bounght a used 340 engine and drivertrain out of a 340 Demon (1971) that had been rolled over in a highway accident.
It had 13,000 miles on it.
I stuck it in my '64 Valiant, drove it for a thousand miles and decided to change cams.
When I took the front cover off the engine, I discovered a factory double roller timing chain (340 standard issue) that had a distressingly large amount of slack in it. It scared me; that's how loose it was.
I replaced it (along with the cam) with a new, stock 318 timing chain with the conventional links.
Dunno how that chain got so loose in only 14,000 miles, but it did.
