there is a b20b1 b20b2 b20b4 and a whole bunch of b20b's.

If its from america, the b20b is gonna have 8.8:1 CR, and make 126hp and 133ft lbs..

If its from Japan, the b20b could make 126hp, 142hp, or 146 hp.. and there really isn't any easy way to tell which one you are getting...

so that leads me to the b20z... which can be bought here in america.

It's guarenteed to have 146hp and 133ft lbs

So if you are looking to do a 2.0L vtec swap, go with a b20z.

If you are replacing your pistons anyways, then it doesn't matter which block because that is the only main difference