Ramshorn casting #s?

I got a set of ramshorns that a guy wants me to sell. He says they are Corvette, I wanna be sure before I sell them off. They are 2.5" dia. the #s I found are3846563. I loooked on several sites already, any ideas? Thanks.

 

they were also used on pass cars AND 'vettes.......hell an ol friend of mine bought a 66 pickup with a factory installed 350 hp corvette engine!

 

Tman, that number was used on 64 Chevy and 64-65 Corvette 327's with 300 horse or more.
Max