Here's one made by Tonno Pro and it's just over $300 because of the oversize charge.
https://www.summitracing.com/parts/b.../c10/year/1986
Here's the same one on Amazon without an overcharge fee, but for some reason they have it listed as 74-83, which is strange.
https://www.amazon.com/Tonno-Pro-42-...00M4914E6?th=1