I got this from LS1GTO, helpful list if your looking to shave some weight off your goat...

After many hours of searching and pulling up numerous threads on weight reduction, I decided to create the ultimate “Weight Reduction” thread. I’ve spent all day trying to get all the information consolidated on one page. This is a composition of various members information. I am in no way taking credit for your efforts or time, just merging the information. If you guys have anything else to add please PM me it me and I will add it to the list. I want to make this your one stop shop for anything weight related.

Remember it takes 100lbs to shave off a 10th of a second in the ¼ mile. 10 pounds of removed weight equals 1 HP. Also take into consideration that the less weight you have the less you engine has to work thus increasing gas mileage.

Unsprung weight is worth way more than sprung weight.

Rotating Mass:

"The use of light-weight alloys in wheels reduces rotational mass. This means that less energy will be required to accelerate the wheel. Given that each pound of rotational mass lost provides an equivalent performance gain as a 10 pound reduction in vehicle weight, the benefits of light alloy wheels on vehicle performance cannot be overlooked.

A reduction in the weight of the rim/tire assembly of 5lbs x 4 (all around the car) is equivalent to a 200lb weight reduction in vehicle weight (thats worth 0.200 in the 1/4 mile)"

Stall Converters, Pulleys, & Flywheels are other examples of rotating mass.

Weight Of Item’s:

Factory Hood: 65lbs.
Skid plate: 15 lbs.
Back seats (both pieces): 45 lbs.
Front Passenger seat (with bracket): 65 lbs.
Fuel Tank Brace: 25 lbs.
Fuel tank brace brackets/bolts(both): 5lbs
Fuel tank top brace bracket (It’s spot welded) 2-4 lbs
Fuel Tank Brace Cover 1.9 lbs
V-Brace for towing: 15 lbs.
Remove V-brace plastic + bolts: 3lbs
Trunk floor cover and fuel cell cover: 6lbs
Strut brace: 3lbs
Stock Battery: 41lbs
Spare/jack/everything in trunk: 50lbs
Spare Tire Cover 6.0 lbs
Front Floor mats: 4lbs
Rear floor mats: 2.5lbs
Torque Converter filled with oil: 55lbs
Owners Manual: 1-2 lbs
Rear seat belt assemblies: 3-5lbs
Rear Muffler heat shielding: 5lbs
Power steering pump & bracket = 11 lbs.
Rear toe adjustment bars: 8-10lbs
Left rear heat shield - 1.5 lbs
Stock spoiler: 5lbs
Hood Scoop Inserts 0.5 lbs
Stock Air Box Intake "Snorkel" 0.3 lbs
Windshield washer container, hoses, and motor : 5lbs
Stock Fan Shroud with Fans 16lbs
Radiator Shroud 1.6 lbs
Stock airbox/filter: 4.5lbs
Stock Exhaust manifolds: 28-31lbs
LH manifold 14.5 lbs
RH mainfold 13.5 lbs
LH midpipe 18 lbs
RH midpipe 14 lbs
Stock driveshaft: 27lbs
Stock 04 midpipes w/ cats: 48lbs
Stock 05-06 midpipes w/ cats: 50lbs
Exhaust after mids until mufflers: 23lbs
Stock 05-06 mufflers: 56lbs
Stock 17" wheels/tires: 53lbs each.
Stock 18" wheel/tires: 54lbs each.
Rear crash bar & foam - 12 lbs.
Rear sway bar - 5 lbs.
Stereo, speakers and insulation/foam - 25 lbs.
Cut out the sheet metal between rear seat and trunk. 10-15lbs.
Both headrests - 3 lbs.
Passenger airbag - 7 lbs.
Both Cats: 15lbs
Power steering pump & bracket = 11 lbs.
Front crash bar = 18 lbs.
Front sway bar = 20 lbs.
End links from sway bar: 2lbs
AC system = 30 lbs.
Fog lights -- 2lbs
Front seat tracks = 20 lbs. each
Glove Box Door: 7lbs.
Underhood Blanket - 2 lbs
Underhood Rubber Molding: 2lbs

Weight Saved thru converting:

Aluminum DS: 11lbs
Change Cross Members to Tubular Type: 22lbs
Odeyssus Battery 12: 20lbs Saved
Factory hood to Carbon Fiber is supposed to lose 20-25lbs.
Headers and catless exhaust - lots of weight saved (30lbs)
Weight going to LT's is 15lbs saved
Weight going to shorties is 17lbs saved
Stock Battery to Red Top: 6lbs
Drain windshield washer fluid: 6-7lbs from full
1 gallon of gas weighs 6.2lbs (Temperature Depending)
Replace front seats with lighter racing seats. 60lb
Pedders suspension. 30-40lbs
Weight of FTI converter: 27lbs filled w/ oil. A savings of 28 lbs
Lightweight Wheels 15 lb +/- per corner 50- 60 lbs
Spares as skinnys - 60lb -- stock are 54lb each
Draglite rears w/bi ply -- 30lb
KWv3 front suspension: 16 lbs saved
Hotchkis front sway: 5 lbs saved
CCW front wheels: 16 lbs saved
CCW rear wheels: 8 lbs saved
Plastic front windshield with anti-scratch, anti-rattle, and anti-fog (10lbs savings)
Plastic rear window with same add ons (10 lbs saved)
All side windows with same add ons (10 lbs saved)
Fiberglass doors from fivestarbodies.com (10 lbs savings total)

Weight Comparisons:

94-96 Impala SS - 4221lbs

1998 - 2002 Camaro/Trans Am
(Coupe) 3400lbs (M6 T-56) + about 150lbs for auto
(Convertible) +50lbs for convertible vs Coupe and + about 150lbs for auto vs M6

1997 - 2004 Corvette
(Coupe) - 3246lbs
(Convertible) - 3248lbs
(Z06) - 3173lbs

2004 Lightning = 4670lbs

2004 Pontiac GTO: 3,725lbs

2005-2006 Pontiac GTO: 3,765lbs

2005 - 2007 C6
(Coupe) - 3179lbs
(Convertible) - 3199lbs
(Z06) - 3130lbs

2005 SRT-10 Ram-5100lbs (or more if quad cab)

2005-2009 Mustang GT:
(Coupe) MT:3,480lbs/AT:3,525lbs
(Convertible) MT:3,610lbs /AT:3,655 lbs

2007 Mustang GT500: 3,920 lbs coupe

2006 Dodge Charger: 3,820 lbs

2006 Dodge Charger SRT-8: 4,200 lbs

2008 - 2010 C6
(Coupe) - 3217lbs
(Convertible) - 3246lbs
(Z06) - 3162lbs

2009 Jeep SRT-8-4819lbs

2009 Challanger R/T: 4,055 lbs

2010 Challanger SRT-8: 4,200 lbs

2010+ 5th Gen Camaros
(V6 Version) Models 1LS, 1LT and 2LT
3750lbs - LT automatic or 3741lbs - LT manual
3769lbs - LS automatic or 3780lbs - LS manual
(V8 Version) Models 1SS and 2SS
3913lbs - SS automatic (L99)
3860lbs - SS manual (LS3)

2011 Mustang GT: 3,605lbs coupe 3,720 lbs convertible