I think you'll find it to be quite simple! Internally, 727's are quite easy to rebuild. 2 sets of drums with sun gears, a front pump (you'll need a set of slide hammers to get that out), and a rear sprag setup. The tailshaft is an important area to keep an eye on. The output shaft has your governor (which contains a valve setup), and it also has the splines for your speedometer gear. I've rebuilt a couple of Mopar transmissions and the one seal that always leaks on me is the output shaft seal where the driveshaft yoke goes in. Not sure why, but hopefully Tactransman has a good tip for you so it doesn't leak there.
Just take your time and keep everything organized. The main guts of the trans can only go back together one way - hopefully that's reassuring!
You going to dig into your valvebody at all?
TABG