Beefing Up the 7.625 10 Bolt Read-End Differential (local copy)
http://www.thirdgen.org/newdesign/tech/beefinguprear.shtml

(found by Paul B.)

Modifying and Tuning your LS1 (local copy)
http://www.vetteguru.com/mods/howto/index.html

(found by Andy)

Throttle Body Bump Stop Mod
http://installuniversity.com/install_university/installu_pages/sophomore_year/tb_bump_stop.htm

(found by Chris)

WS6 Ram-Air Mod
http://www.geocities.com/brian98ramair/Cold_Air_Pics.html

Tire Survey
http://www.tirerack.com/tires/surveyresults/uhp.jsp

F-body cars installs/fixes
http://www.bfranker.badz28.com/fbody/GuidesTop.htm

LS1 installs
http://ls1.fbody.com

LS1 mods install/reviews
http://www.ls1info.com

Gear Calculator
http://www.f-body.org/gears/

(found by Rick)