timing belt change questions

[alloro]

91 Lumina, 3.4V6 motor with 96K miles. I'm replacing the timing belt, both idler pulleys and the tensioner pulley. My question is about the tensioner/actuator. I see from reading this forum that it is a good idea to replace the actuator while I'm in there.

1. But considering the low mileage, is it really necessary?
2. If I reuse it, I see from reading the "how to" on this site that it has to be filled with oil. Is this motor oil, how much and if so what weight? (10w30, 10w40, etc.)
3. Can I avoid opening the top of the engine to time the cam, or can I just trust the factory yellow timing marks on all of the pulleys?

Thanks.

[napatiger]

retract actuator with small screw driver and paperclip, then fill to bottom of plug hole with 5 30W synthetic. It takes a while for oil to fill, you will have to fill, wait, fill, wait, ect..

[alloro]

Okay, thanks for that information it will be helpful.

Anyone have an answer as to whether or not to reuse the old one or definitely go with a new one? How about the factory timing marks question? Thanks.