Carlos Beltran is taking a Giant leap to first place, and the Mets are a building block closer tofuture success. After weeks of trade discussions involving Beltran, the Mets yesterday agreed to send thebest hitter available in this trade market and $4 million to theGiants for top pitching prospect Zack Wheeler, multiple sourcestold The Post. The deal will not become official until today because there is a24-hour grace period for players with 10-and-5 rights (10 yearsmajor league service, five with the same team), in case the playerdecides he wants to rescind the trade.