So i recently bought a 09 dodge ram hemi. I wanted to put a 4 inch lift on it,but found out that i had rear airbags. If i were to fill my air bags and put a leving kit in the front would i run into any mechanical problems in the future ?

 

Depending on the Brand, Most say you should not run a constant high pressure in them. Most say to run at 5psi when unloaded. Buout in theory no. I have a 2010 running Bilsteins 5100 set to 2.7" to level it out. In my setup, the front and rear are within .5" of each other. Good enough for me. No problems yet. I also have the firestone airbags for the rear. I leave them at 5psi except when towing. When I tow, I will crank it up to 35psi then grab the tape measure and let out a little air until I set about .5" higher then the front.

 

I have Air Lift in the rear of mine. Only keeping the min of 5 psi. Doesn't really give it a harsh ride either. Great for towing.

 

I would not run 'support' bags to lift your rear up.

I would run 10psi in the one's I had when not in tow and 20-40psi when towing depending on load. My bags could handle 100psi and would lift the back up about 2" over stock.
Very rough ride when driven at 40psi and no load. The back would jump around. Being a 2009 and independent rear you should not have that probblem but it will be a rough ride regardless running high psi when not loaded.