I pulled the heads off my 92 z28 and ran the number through mortec and I don't think they are the original heads that came on the car. I could be wrong but the number is 14101083. Come to think of it maybe the block is not the original, it's number is 10243880.Can somebody tell me more? Thanks for any input.

 

083 is the correct L98 head casting.

The block is almost certainly a replacement one.