Here’s a great article I found on Golf.com a few months ago.
Forty years ago, being tall was viewed as a big disadvantage on the PGA Tour because players didn’t have access to club-fitting systems; they had to adjust to their clubs. Players had to manufacture a swing to create the preferred trajectory or ball flight they desired. Nowadays, manufacturers can accommodate the swings of all players, whether they stand 5-foot-8 or 6-foot-4, like this weekend’s AT&T Pebble Beach National Pro-Am champion Dustin Johnson.
Players such as Johnson, Davis Love III, Phil Mickelson and Bubba Watson now hold an advantage because of their height, especially off the tee, since they can make the clubhead travel on a longer, wider arc. Since it travels a greater distance, there’s more time to make the club go faster. That’s why Johnson is able to generate ball speeds of 190 miles per hour.
Most tall golfers I know can’t dream of producing that kind of clubhead speed and power because they’re not properly fitted for their clubs. In most cases, they’re buying their clubs off the rack. Tall people everywhere: If you want to hit longer shots with greater consistency then you MUST go see your local PGA professional and get fit for a set of clubs (and that includes your driver!). The second you have to accommodate the club to your height and swing, you lose your advantage.
When you address the ball, you should be able to stand tall with your back relatively straight and your arms relaxed, hanging under your shoulders. If you find that you have to bend over a lot to reach the ball, or your arms are outstretched and stiff, then your clubs are too short for you. Once you’re fit into a set of clubs that suits your height and swing, then you’ll be able to get that extra width and distance you’ve been expecting.