Tweaking timing on the diesels?

[Backside180]

Anyone have any rules of thumb they care to share on tweaking timing when turning the power up on a diesel? Logic says retard, but looking at a few tunes in the repository it looks like most advance if anything. How do you know where the limit is (With gassers you have the knock sensors)?

Thanks

[blued turboed1]

What year truck are you tuneing?

[Backside180]

What year truck are you tuneing?

2004.5 LLY