Fiberglass 1/4's and hood?

I'm not sure if this has been covered yet? But I'm thinking of replacing my 1/4 panels and hood with fiber glass ones. But only if the weight savings is great enough? Shaving a few pounds isn't really worth it to lose the steel. But if your talking over 100lbs plus, it seems well worth it? Does anyone have any real number on weight savings? Also, if it's worth the weight savings does anyone want to buy/trade a '68 340s hood? It's in really good shape? My car was made into a 340s clone sometime in the 80's before I bought it. It was a 318 automatic car from the factory. It has a 340 4spd in it now.