What could be causing this on the front end?

Where did you get an alignment done? I hope you did not get it done at a truck stop. It is always best to take it to an alignment/spring shop. It is possible your right front wheel bearing is going bad where the spindle. Also check the steering axle brake adjustment. It's possible you're right front brake camed over

 

Check to see if the s-cam or slack adjuster is bad or sticking and causing the brake on right side to drag causing the sound and pull.

 

As to the flapping noise... I had a ferring loose on the rear passenger side of the sleeper. I could have swore it was something under the hood, and it took me months to find it. Once I fixed the loose ferring the flapping noise went away.

 

Swap front tires if it pulls the other way it’s a bad tire. Happen to me recently after alignment!

 

I would check hub bearing/spindle or could be broken /weak brakes shoe return spring.

 

When was the last time you had your drums pulled off and the rollers, cams and bushings looked at, cleaned and lubed or replaced?

I had this problem on one truck, the driver had it checked a number of times by different dealers and it ended up at a hole in the wall shop somewhere down in Alabama run by old guy without any teeth, he listened to the driver, kept nodding his head as the driver kept on and on, when the driver asked if he got it, he said "after your second setance, I knew what the problem was, you were trying to go around an open barn instead of just walking through it" so I get the call for the approval, talk to the guy and he said the problem is with the s cam and rollers. He said he is going to replace everything and the truck will be right.

He was right.

 

I worked for a company that did in house alignments. Truck still pulled terrible. The old fat guy just shrugged his shoulders and said it's aligned, that's all we are going to do. Eventually I came in and the night manager heard me talking about it. He looked the truck over, and said go take a break, and when I came back he had taken the Bridgestones off and put on Michelins. Drove like a Caddy after that.

 

I would definitely check the wheel bearings. I have had them make a grinding noise. If it has the permanently sealed bearings, look inside the brake shoes/drum for metal shavings.