SainSmart 20 x 4 LCD wanting to use I2C from Arduino Uno

Using Arduino Displays
15

I am so close I feel it...I just need some new tips....

here is my code:

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x3F, 20, 4);

void setup()
{

lcd.init();
Wire.begin(0x3F);
lcd.print("Hello");
lcd.setCursor ( 0, 1 );
lcd.print (" World!");
Wire.endTransmission();
}

void loop()
{

}

pins 4 and 5 from arduino Uno plugged into I2C board on 20 x 4 LCD...along with ground and power.....just white pixels on LCD still and the LED backlight flashes from time to time.....