This bumper is designed to be used with stock '74 and on 911, SC and Carrera 9" quarters and flares or GT Racing rear quarter panels (part #35-9, 36). Lot's of folks use this bumper to quickly change the look of their car from the old impact bumper style to the old school narrow body RS style. This bumper is also very popular with the spec type of classes in racing and the folks who want an easy light weight great looking solution. Average weight is 7 lbs. Original from factory is 52 lb. GT Racing also recommends the matching front bumper Part #43. Call for carbon fiber pricing.