I've got a glass bumper on my Chevelle.
Not totally the same scenario, in that my steel bumper was 60 lbs, and there was another 60 lbs of structure in behind it, so the savings in weight of the bumper itself but also the mounting structure was significant (It's held on with 1/4" by 2" aluminum flat stock now).
You will have the opportunity to decide what color you want (for me: argent vs chrome plated). You could also do yours body colored, which might be cool (not an option for me).
Yours will be a pretty tight fit to the front end. Depending on the supplier the glass as received will probably fit pretty crappy and will probably take some tuning to get it to match your specific car. VFN makes good stuff; my parts are only available through US Body Source, the quality of which is kind of marginal.
One other consideration: you will no longer have any crash protection on the front end. My bumpers extend out past the sides of the car so once every five years or so I hook them on something and tear the end off.
K
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'63 LeMans Convertible
'63 Grand Prix
'65 GTO - original, unrestored, Dad was original owner, 5000 original mile Royal Pontiac factory racer
'74 Chevelle - original owner, 9.85 @ 136 mph best
http://www.superchevy.com/features/s...hevy-chevelle/
My Pontiac Story: http://forums.maxperformanceinc.com/...d.php?t=560524
"Intro from an old Assembly Plant Guy":http://67-72chevytrucks.com/vboard/s...d.php?t=342926