I am just wondering if i go with a bigger shackle running a +2 now go to say a +4 or so. Will this push my axles forward? or will it be about the same just wondering what all imight have to do besides brake lines. Thanks

 

Won't really affect the axle location all that much, that is controlled by the front half of the spring and the spring hanger location. Assuming you are talking about the front axle, the longer shackle will push the axle farther away from the frame and give you more tire clearance at the back of the wheel well:
- http://www.4crawler.com/4x4/ForSale/Shackles.shtml

 

I put 4 inch shackles on my front end and had very bad axle hop, i instead built 5 inch drop hangers in the front and it made a huge differnce, pushing the axle back

 

of course i dont know what kind of wheeling you do but mines 50% mud 50% clay lol