If you can hit your 3 wood around 300 yards or your 1 iron 275 yards consistently, there is no reason you need a driver in the bag to get your handicap down to a 3 or 4. I'd assume that you need more help in your short game than trying to get longer off the tee.
Do you pace out your yardages from tee box to the ball to know how far you are hitting your clubs? I'd love to see a video of someone hitting a 1 iron 275 yards. Definitely would be a sight to see.