well i was told this by a guy at the honda dealership and also i read it in a honda tuner book that i bought so yea it should be a 99, either way its only 1 year off, if it is a 99 and not a 98, and yes they could have put a 99 head on the block as well, as far as the block and head goes on the b18c1 motor they were all the same from the first year they were made until the last year, only difference was the wiring that was used to connect it to the car. They may have just wrote the wrong year by accident or changed the head for some reason, which would scare me cause why would you change the head unless something had gone wrong with it before u got it, anyway I wouldn't worry about it that much as long as the compression and leakdown tests were good and you don't hear any knocking u should be in good shape, but i hope u did get a warranty! Hope this helps.