i want to now wat mark to used

I think you're asking about how to set the timing? Cam timing or spark timing?

Do you have a timing light?

I think that he wants to "Put back the timing chain" It usually reads better if the text is checked before being submitted.

It's all explained in detail in the workshop manual. These are regularly seen on ebay at very reasonable prices & are the best investment you can make if you plan on doing your own work.