I didn't find rebuilding a 350 to be all that hard my first time, just take great care in checking out how things come apart and take pictures. I had to do it 5 or 6 times until I had no pieces left since I didn't pay close enough attention when it came apart. I got an Illustrated Parts Breakdown from a book at the library, but I should have bought the Chevy Tranny book.
Depending on what engine you have, I would stay with the 400. Stronger engine, and a swap to a 350 will require modifications.
Good luck to you, and if you need any help on the way, this place is the right place to ask.
(oh yeah, and by the way, the rating would be a 6 on my scale, way below dismounting a tire with no tools, and way above putting gas in it!
70 Impala Sport Coupe (283)"Green Goddamn!"
63 Oldsmobile Dynamic 88 (394)"Hoopty"
61 Chevy Stepside Pickup (350)"The Pickle"
49 Plymouth Special Deluxe (427)"The Mayflower"
77 Chevy Blazer (350)"The Moo Machine"
66 Chevelle (I wish, still looking)
[This message has been edited by ledsled (edited 11-05-2000).]