I got a new flex fit front bumper from Ken’s Corvettes (they got bought out about a year ago) and the fitment was pretty poor. I think they all are, execpt of course if you’re going to replace yours with urethane. I had to fill about 1/4” on each side of my bumper. From what I was reading they all pretty much come from the same supplier. Mine was supposed to be the brand Ecklers uses so i expected good things. I guess these cars were hand layed so usually they don’t line up well.
I’d say Corvette Depot’s will probably be the same as the rest. As far as the mounting goes the urethane uses a metal retainer with threads and nuts that pintch it to the body. The flex fit or fiberglass use studs with nuts and don’t have the metal retainer that goes around it because it’s rigid enough.
Here are some pictures of mine and what it looks like underneath.
Hi. I bought a truflex rear bumper cover from Ken’s Corvettes a few years ago. I liked the truflex because it was more rigid than the original urethane (no waves and no cracking with age) and more flexible than fibreglass (no cracking in case of a gentle bump). Because all C3 Corvettes vary marginally in size due to varying humidity, temperatures etc. when body components are being molded these bumpers are made slightly smaller. This avoids the need to repaint fenders (or perhaps the entire car) as would be the case if they were too large and you had to build up the fenders. You may get lucky and find it fits your car acceptably but more than likely you’ll need to use some flexible body filler and lots of patient sanding. They mount with stainless steel fasteners, no need for the original mounting strips. Follow the provided instructions, be patient and you’ll get a satisfying result. Hope this helps.