On the Alpine system you have to wire separate as the lines form the amp are already crossed over. If you just use one you will lose highs or lows if you just hook up one of them.
You may need to flip the mounting bracket on the lights to get more adjustment in the angle the light is pointing. I had the same issue before I realized flipping the light bracket around fixed the issue.
The front looks to be close to 3 inches, but the rear fenders must stick out more as they look more like 2.5 inches. I see if I can get some pictures. I will say it driver better with the wider stance.