Interesting swap. I'm a 6.0 fan myself but that 5.3 should work nice for you. Too bad they didn't swap in a 60E instead of that 700, then you would have total control of both the engine and trans with simple key strokes
![Wink](http://67-72chevytrucks.com/vboard/images/smilies/wink.gif)
It will take alot of trial and error on the 700 to get the shift points in a happy spot for that 5.3.
If you had HPtuners I could send you a stock 5.3 tune file so you could flash that in to start with. I can tell you though they need alot of time tuning and tweaking to optimize even a stock engine.
Neat truck, and a good deal considering the coin it takes to do an LS swap and do it right. You'll have some fun with that.