You need a powerglide rebuild kit. I had a B&M Master Overhaul kit that I used to rebuild mine. Includes all seals, gaskets, clutch packs, etc....
Also would be nice to get the Powerglide Transmission Handbook (I think the author was Carl Monroe) It gives pretty clear directions on rebuilding powerglides along with helpful photos.
Active Navy 92-99
Army National Guard 00-05
Navy Reserve 05-Present
Served onboard USS Carl Vinson ( 2 Westpac's)
Served in Afghanistan OEF IV 03-04
Going for 20 !