Blog posts with old date...do they carry good weight?

I'm wondering if I pick some of my blog posts...manipulate their post date and make them seem like few months ago. Would that create some sort of a good weight for the SE's?

nope. date of the post does not affect ranking

no.

The age factor in serps is the one given by how long that particular website/page has been indexed.

Ex, a 10 year old domain that was indexed in google only for one year is less valuable than a 2 year old domain that was indexed in google from the beginning.

The same applies to domains, and pages age, and stuff. They started to exist for serp when they have been indexed in google - and google uses its own cache data - not when they have been created.

that was quite an explanation Nick.. makes sense..

yeah he nailed it. thanks Nick Flame