An '07 will have an MDS engine...so (from what I've been told) you need to use to correct oil (5w-20)or the MDS system will not work properly. If I'm wrong on this, somebody please correct me.

My 2006 truck (currently 205,000 mi) has a 5.7....I initially ran dino oil changing at about 4k miles. I switched to synthetic at about 80k. I run the extra long Baldwin filter (the filter alone holds almost a quart), and usually get Quaker State full synthetic, though I'll buy whatever name brand if I find a good price.

Usually go about 5k between changes. It is just getting to the point that I have to add a small amount of oil between changes.