How do I tell??

SOOO I just bought a 1998 Honda Civic ex that was already swapped with , what the seller said, JDM B16A2 DOHC VTEC engine. He also mentioned that if I were to buy parts, I need to buy parts for a 1999 civic si because apparently that's where the engine came from. But I looked at the engine code stamp and it says "B16A" with no number at the end. There's another code underneath it that reads "1039150". I read previously that if that number starts with a one its not an b16a2 but a b16a first gen. Idk what to believe now. Help me out..?

Also, I forgot mention, he change the valve cover with a mugen valve cover of that makes a difference...

It's a JDM engine, because it doesn't have a number after B16A.

To tell what year/generation it came from, the year the engine was produced is stamped on the front of the engine.
http://img.photobucket.com/albums/v473/CivicSpoon/engineyear.jpg

It might not be directly at the center of the head, like it is in this picture of an H22A engine. In fact, I believe it's more to the left side of it., but still in that general area.

But generally, yes, you will buy engine parts for a '99-'00 Civic Si, regardless of the year the engine is. Not much was changed between different generations, or from JDM vs USDM.

Yeah. But the thing is the engine that is already in the car is siezed up and I'm looking to do a rebuild. I need to know what kind of engine block I need. I'm just confused because the seller said b16a2. And i did my research and people are saying if it says "B16A 1xxxxxx" it's a B16A1 and if it says "B16A 5xxxxxx" it's a B16A2. So what you're saying is it doesn't really matters what block I get?

True JDM engines don't have a number after B16A.