I forgot to add - how far back you'll actually be able to incline the body will depend wholly on how much weight is on the bar. More weight + more possible layback.
Check Aimee here- http://www.cathletics.com/resources/...snatchPull.mov
Now Aimee is not the greatest puller in the world (she tends to slow down a bit too much during the scoop and scoop a little early, as well as round her shoulders forward at the top....) - but this is a decent pull at a very light weight. You can see that she has to extend straight up because it's so light. But that is much preferable to pshing the hips forward.