I found the timing chain replacement write up for om616 and om617 s would that be the same for my motor?

I thought people said after 4 degreesto change the chain? or should i?

__________________
Dave

1985 190D 2.2 auto--gone
1975 240D 4-speed--storage
1985 500SEL--daily driver
1985 300TD--bad rust, soon to part out...
1982 300SD--waiting on engine from RD
1984 190E--storage
1996 Dodge 2500 Cummins--daily driver