Join Date: Sep 2000
Location: Washington, Michigan USA
I doubt if you could even measure any meaningful weight savings for the fiberglass inner fenders vs. the steel ones, unless they're REALLY thin; the steel ones fit fine, and don't take much prep work at all for painting.
There isn't that much weight savings with fiberglass, or C2-C3 Corvettes wouldn't weigh 3200 pounds; fiberglass is used in low-volume applications because the tooling is dirt cheap compared to the huge cost for steel stamping dies, not because it's any lighter than a comparable steel part for the same application. Race-car fiberglass is light because it's paper-thin; production-car fiberglass has to be thicker for surface quality and durability, and is no lighter than a comparable steel part.
I'd go with the steel parts and avoid the paint prep and fit hassles. I've worked with fiberglass all my life in the Corvette side of my hobby, and GOOD fiberglass parts are made in a press using SMC (Sheet Molding Compound) and matched steel dies (only requires one set, vs. five or six progressive die sets for a steel part); the other 99% of aftermarket fiberglass parts are hand-laid in the open in one-sided molds made of wood, plaster, or epoxy, are nowhere near as strong as a press-molded part, and are only smooth on one side.
Same old story - you get what you pay for, and the guys who make aftermarket fiberglass parts can't afford the tooling and processes to do it like a production part, so you get to do all the fit, finish, and paint prep work, and then live with the stress cracks, resin-rich corners and edges, etc.
'69 Z28 Fathom Green
[This message has been edited by JohnZ (edited 09-25-2001).]