Gary Sheffield presently has 1,494 career RBI. With 6 more, he hits the 1,500 milestone mark.
There are only 21 right-handed batters in baseball history with 1,500+ RBI. And, by rough eye-ball scan, I would say that 99% of them, who are Cooperstown-eligible, are in the Hall of Fame.
For what it’s worth, Frank Thomas and Manny Ramirez should enter the 1,500 RBI club later this season as well. The next RHB to make it would be A-Rod or Jeff Kent, but, it will probably take them around 2 years to get there.