By using lead weights you can dramatically change the way your racket plays.
All the pro's have some sort of lead weights added to their rackets to personalize the racket to suit their game.
Now I am not a racket expert, so this needs you finding someone who is in your club or area, but below is a rough idea of depending where you put the lead, the difference it will make.
Locations for Lead Tape
Sticking tape in this position will give you a big power boost and expand the sweet spot toward the tip of the racquet, which will appeal to baseliners. The potential downside? The racquet might become head-heavy and cumbersome.
10 o’clock and 2 o’clock:
Weight placed at these positions will increase the frame’s power, add stability on off-center hits, stretch the sweet spot toward the upper edges, but also reduce maneuverability significantly.
9 o’clock and 3 o’clock:
The most popular configuration enlarges the sweet spot toward the sides of the frame, where players frequently mishit the ball, and makes the racquet considerably more powerful.
If you place tape here, your racquet will be a bit more stable, a bit less maneuverable, and a tad more powerful. The sweet spot will be pulled down, which will help those who miss shots low. Handle: Lead tape under the grip will increase the racquet’s stationary weight with little effect on swingweight (how heavy the frame feels when you swing it). This position is best for net-rushers who want a heavier racquet without sacrificing maneuverability.
Now if you click on the tenniszoo link, you can view all this on the TennisWarehouse web site.