If you are just breaking it in, keep in mind that the initial run in is only a few tanks...The engine isn't fully broken in for 1/2 to 1 gallon. As it wears in, and you lean it for performance(still too soon for yours), you will see those high revs. I don't know if it will rev as high as the 2.5, that sucker revs to the moon, but you will see better performance after it gets fully broken in, making you a better driver, and your truck will put in faster laps.

It sounds like the lsn is set just fine. Just be aware that it will load up if you leave it sit and idle for a while. While you are driving it you can stop and then pin the throttle and it rips, right? That is what you are looking for. The fact that it idles for an extended period of time, and you are still able to drive it away, means good tune, to me.

Make sure that the carb is tight enough not to move by hand. This will vibrate loose and cause an airleak, making tune an unattainable dream, and usually cause overheating and early engine retirement.