Amc hood scoops

If dimensions are the same I would think it comes down to price and  how you are going to attach the scoop to the hood. Fiberglass is bonded bolted or riveted and metal has the option of welding to secure it. 

Mike Pierce ,owner of Pete's Patriot also has the steel Super Stock hood scoops. They are made of the same gauge steel as the originals and are the same as the one's that are on Cotton Candy and Gold Digger, both cars have the original scoops and these repo scoops are made the same. Painted, side by side you can't tell them apart. Other Super Stock's may have had a scoop that was a little different, I don't know but Cotton Candy and Gold Diggers look the same and their numbers are close to each other so these scoops were made to that pattern.  

I went with the metal one from Mike Pierce, really nice , now i have to finish the car

The fiberglass scoop on my Javelin is a bolt on but it is also a hemi Dart style, no problems with it and there are probably 10 bolts or so. Got it from VFN fiberglass. 

jeremy0711 wrote: this could be a no brainer but.... if you were to compare a weld to a glue version and which would outlast the other.... A glue is suggested for a limited amount of time-type bond and a weld is a permanent type of bond. It comes down to.....how well do you weld?   I would weld one on. My limited welding skills would outlast a glue on version any day. No contest here, go metal!

Where do you get the "limited time" bond thing? Who says?
That "glue" is used to attach full-size body panels, for the life of the car. It's used in industry to bond things that are under more stress than a hood scoop would experience. IF it's properly done, the specs get into the tens of thousands of pounds. Will your scoop experience that?
People have a fear of such things due to the past - experiences with JB Weld, cheap adhesives and the "but wait, there's more!" advertising for cheap products. Lord products are used to "glue" the tie-down rings in semi trailers! It's used for aircraft panels.
With the adhesive bond, the adhesive seals out the processes that cause rust. Welding promotes those processes.
You heat the metal and it's a good place for rust to begin. The experienced folks around where I live who do body work and welding seem to agree on that - when you heat to weld, you may be opening a chance for corrosion where there wasn't a chance before. Maybe in Iowa we prefer to avoid rust...
The car makers approve of - and even use such adhesives. And you'd not use it on a simple hood scoop. It's on hundreds of thousands of cars right now holding on entire body panels, and used to attach patch panels on thousands of cars - with no problems. My neighbor has used it on two pickup trucks to attach large body panels under more stress than a 1 or 2 pound scoop sitting on a hood .

With the adhesives available today, I'd seriously consider the chemical bond.
I'd also strongly consider it because of the large reduction in body work needed to make it look nice.