Anyone have any idea how many miles, out of a 05 STS Cadillac

Timing chains will usually last the life of the engine. If you skimp on oil changes your engine will not last long.

Ive stayed on top of my 05 cadillac with oil changes and a few other repairs, like the C- converter and motor mounts. I have 189.000 miles on this engine. no problems yet. I fixed up really nice and changed out the radio and interior. I like it so much im thinking of getting another engine with lower miles.