A master kit , a new band, some bushings, filter will cost under 200 bucks.
Replace every clutch and steel while you're in there.
ATSG service manual is good. I also referred to a Haynes Automatic rebuild manual when I did my first one.
Use a core 1988 and up. Not a big deal as you'll need a new convertor anyways.
You can make yourself alot of the tools you need.