I just turned 320,000 miles and was thinking how good my car has been running. Does not burn or leak a drop of oil. I started to think about the timing chain and related parts. I have TONS of service records but none related to the replacement of timing chain. I adjusted my valves around 280,000 miles and the chain seemed fine then. I just wanted to be proactive.

What is the replacement interval for the chain and guides?

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'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R