I think I might have an engine from a 1955 Corvette. It sounds like only 6 or 7 1955 Corvettes came with the 235 six cylinder blue flame engine. the casting numbers are 11 GM 3835911 the stamped numbers are 0019463 F55P. I wonder if this engine is worth anything?

It is the correct casting number for a '54 (late) or '55 6 cyl engine
As for the block number, they were sequential, Noland Adams has a good book about the old ones, but that's not your question. I wouldn't scrap it, advertise in the Driveline, the corvette publication that goes to lots of corvette owners, I'm sure someone would want it, even if for an extra.