Bump stops have no effect on turning radius.

If it's, in fact, your axle hitting the chassis, yes, longer bump stops would keep your axle from getting as close to the chassis as it does now.

I think they come in different lengths so I'd use a heavy duty ratchet straps to compress your springs to the point maybe an inch from the chassis (you want to allow a little for the compression of the rubber bump stop) and take your measurement to see how long they need to be. At the same time you can make sure the axle isn't too close to something else.

That said, fish is right that it makes no sense you'd be hitting the chassis after the lift when you weren't before. But you can still use the method I described to really tell what is hitting,.

 

Its IMPOSSIBLE for the axle to be hitting the stock bumpstops after a 2" spring spacer lift. Think about it........if your axle was 5" away from your stock bumpstops before the lift, the axle would be 7" away from the stock bumpstops after the lift.

YOU need to get under the truck while your dad and brother push up and down on the front. Figure out where the banging is coming from. Pay attention if it happens when the suspension compresses or rebounds.

**** Wait a second.... Isn't there some issue with the driveshaft hitting the swaybar or frame crossmember when a D2 is lifted???

 

When it is lifted an unadjusted Panhard would move the axle left (drivers side). Just looked at mine. But I have way over two inches of lift (and now an adjustable Panhard but I went without for a couple of years) and nothing touches. That's interesting. Have to look that up.

 

The spacers are between the spring and axle, I did not get extended shocks, the front shocks are still at stock height since they are attached to the spacers as well.

 

The banging noise is at the end of compressing. When it bangs the suspension will not go down anymore and causes the suspension to go back up, whatever is hitting what is causing this.

 

And what's hitting?

 

You don't expect him to crawl under the truck himself amd check do you!?
Its much easier for us to troubleshoot over the interwebs.

 

Okay, so the spacers sit below the spring perch I suppose. I have those, too. That would extend the space between the axle and the frame and other hanging components and make any bumping LESS likely due to compression but it would also kick your axle to the driver's side a little if you have a fixed length Panhard bar.

So, while I didn't have any issue with 2 inch spacers and an additional 3 inches of longer springs, you may have the problem suggested by someone else. I would compress the springs as described elsewhere in this thread or as you have before but have someone underneath find out where the touching occurs.

Honestly your springs must be a little worn if two people can compress them.

 

That is what I can't figure out, me and my dad bounced on the front of the car and my brother said it was the axle hitting something, the bump stops or maybe the frame, we still can't be completely sure.

 

That's when you say "let me under there to see, that doesn't sound right". You're not going to learn anything by taking someone else's word for it.
I seriously doubt it's the axle being shifted.
The only way for this to get figured out is for you to get under there.