I'm afraid I have bad news for you...There are four GM part #s for 2.5" Corvette ramhorns. They were all available last year and cheap. This year they have ALL been discontinued, with no warning. The Corvette guys grabbed them all up as soon as they heard the news.
Dorman is making one of these repro/China. They are pretty good. I compared them to the GM and the repros are a little more restrictive, but not bad.