Hi, I'm new to these forums. I have a 2005 Dodge Durango that I'm looking to beef up a little. I'm thinking that I wanna add some bigger all terrain tires, cold-air-intake system, and possibly a cat-back exhaust. Anyone have any suggestions on makes or models of any of these items??? I'm looking to get the biggest all terrain tires I can put on without compromising safety. I'm looking for reasonably priced parts without a lack of performance. Any help or comments would be appreciated, thank you.  

What Motor???????????  

It's got a 4.7 V8 magnum.  

You better install some new deeper axle gears or is will be a slug and MPG will suffer more too. Also for what it is worth, bigger tires and lift do not real make any truck more HD because they actually weaken it because they place more strain on axles even with static loads so do not get carried away if you plan to play hard. Furthermore cat back can ad sound but they actually reduce lower RPM torque and response and can hurt city MPG too for what it is worth.  

Really, I heard the opposite on the cat-back. I heard you get better combustion and it increases the efficiency. Nor have I heard anything about the stress the tires would be putting on the axles. Thanks for the info.  

ALSO THE BRAKING SYSTEM ON THE FRONT IS PRETTY BAD STOCK,(BAD PULSATION,FAST UNEVEN WEARING OF THE ROTORS AND PADS)YOULL BE EATING ROTORS LIKE CHEESECAKE!SO IT WOULDNT BE A BAD IDEA TO UPGRADE TO A BIGGER BRAKE SYSTEM.THATS ONE THING ALOT OF PEOPLE OVERLOOK...WITH BIGGER/HEAVIER TIRES YOU NEED TO STOP SAFELY AND THE STOCK SET UP WONT LAST AS LONG.  

There is not much of an after market for the 4.7, Check out www.Dakota-Durango.com and you can find out all you need to know about your year Durango and possible power upgrades for the 4.7, as far as the Suspension aftermarket you are pretty limited. The suspension after market has always bin limited for these trucks  

Durango05:
Really, I heard the opposite on the cat-back. I heard you get better combustion and it increases the efficiency. Nor have I heard anything about the stress the tires would be putting on the axles. Thanks for the info.

You need to understand that is is a burn in cylinders not a explosion and it is the expanding gases from burn the drives piston down. If you lets guess out too soon at lower RPM torque will suffer (the reason low RPM power is poor with high overlap cams) Stock the exhaust system is tuned to not let gas escape too quickly so more of the energy is coupled to piston. In the scheme of things, the time duration in mil sec the valve is open at lower RPM is a lot longer than at higher RPM so less back pressure can help sometime above 3500 RPM. Detroit spends a lot of time tuning engine for a broad power range and a chopped exhaust throws that out the window or so. On axle strength, the rolling radius is increased to axles have to carry more torque to put same effort on tread on road plus bigger tires and wheels change load center relative to axles and bearing and place more strain on them. There is a lot less safe "wiggle" room for the extra strain on a LD 1/2 ton or such than a 3/4 or 1 ton.