Here are a bunch of links for rebuilding, performance tuning, manuals, rebuild kits, etc for C4 and C6 automatic transmissions:

C4 Rebuilding parts/kits:

http://www.broaderperformance.com/c4...sion_parts.htm

http://www.transmissioncenter.net/c4_c6.htm

http://www.tciauto.com/Products/ServiceKits/default.asp

http://www.drivetrain.com/parts_cata...nd_trucks.html

http://www.atiracing.com/products/re...rebuildkit.htm

http://www.transmissionpartsusa.com/...ts_s/11592.htm

Kits plus rebuilding book:

http://www.campbellenterprises.com/a...ebuild-kit.php

Rebuilding C4 links:

http://www.redfalken.com/pages/c4.html

http://www.customclassictrucks.com/t...ild/index.html

http://www.mustangmonthly.com/techar...ion/index.html

Videos:

http://video.google.com/videosearch?...d=0CD0QqwQwBQ#

Manuals and kits:

ttp://www.google.com/products?hl=en&rlz=1B3GGGL_enUS339US339&q=c4+trans mission+overhaul&revid=1964226815&resnum=0&um=1&ie =UTF-8&ei=4v09S_y2MMeztgeX0e3-CA&sa=X&oi=product_result_group&ct=title&resnum=3 & ved=0CCkQrQQwAg

http://www.themotorbookstore.com/fordtranny.html

From Adrian(Twisted Bronc):

http://www.c6-c4.com/