318 to 360 conversion

I have a 2001 ram 1500 with a 318 and auto trans ,I would like to change to a 360. I was told this is an easy swap. Has anyone had any experience with this  

Engine should be a bolt in but then there is the electronic have to match it too for ECM and controls. Also 360 are not known for fuel efficiency. I would suggest that is your motivation here is better performance, a 360 is not a big upgrade and you will gain a lot more bang for your truck if you regear axles. 1/2 ton truck with 318 tend to be geared pretty tall and that truck with a new set of proper axle ratios and a 318 would run circles around same truck with stock gearing and a 360. The 318 is a good sturdy motor and with proper gearing it can do a fine job.  

MY 318 has 200K and I am pulling a 3500lb trailer. I was hoping a fresh engine and more cubes would make towing a little easier, especialy at highway speeds 65-70  

Fresh engine would help but if you tow a lot so would gears. Performance wise in stock condition there is not much difference between them  A stock 360 has 10 more HP and 10% more torque which is not much.  

Having owned more than my share of Mopars, and doing several swaps and upgrades in the newer Rams, I would either rebuild or replace the 318 with another 318. The power gains of a 360 (both torque and HP) are very minimal. You already have the computer for the 318, just give it more gear!
We just swapped my friends 3.55's for 3.90's in his '96 1500 2WD with 135k on the motor....holy crap! it made an amazing difference, even in a basically stock truck!  

I pull a travel trailer and a 65mph I'm turning 2500 rpm, I keep the overdrive locked out but it won't shift up even when its turned on. I run out of power even on short uphill pulls. When the truck was new I was pulling a pop-up trailer, now after 8 years I've gone to a hardside trailer that weighs about 3500 lbs. I'm trying to find an alterative to buying a bigger truck.  

You need to be turning more than 2500 RPM in drive at 65 with a trailer. It does not upshift because engine is lugging with trailer load. If you increased engine RPM about 10 to 15% in drive at that speed with deeper gears you would have more HP available to move load. This is for a two reasons. First HP is a function of torque and RPM (the higher the RPM the more HP is available) And second, your 318's torque peaks at about 3200 RPM and the closer you get to that peak in drive at 65 MPH the more pulling power you are going to have. Right now at 2500 RPM you might be making about 250 ft lbs of torque and that equals about 120 HP available at flywheel. If you got RPM up to say 3000 RPM in drive at that speed you would have closer to 160 HP available. This is a big difference and possibly more because I only used 280 ft lbs rather than rated 300 because engine may be a bit tired. (also consider of that with current 120 HP at fly wheel, 20 to 30 HP is lost in drive train and another 30 to 40 HP to power truck which means you have only about 50 extra HP left over for load. Another 40 HP would nearly double the amount of reserve power (because drive train losses would be same) and make a big difference towing.  Plus, engine would also upshift to OD under light load conditions with trailer because less torque is required from it to cruise with deeper gears. Engines also tend to be more efficient under heavy load when operating near their torque peak and MPG should improve towing. Even a 318 can move a lot of weight with right gearing behind it so it can use its available power better. Furthermore a side benefit of this regearing would be better power for starting out load and when backing load up too and tranny will run cooler because it will handle less average torque to move load. Deeper gears is a win win scenario towing.