Buy the cummins. seriously, I own a hemi but the cummins is a more reliable motor and you can tow a mountain. also with a few mods you could run an extrememly fast 1/4 in a diesel.

 

I had a 98 Ram w/ Cummin's and it did a great job of towing our 30' 5th wheel (5-6 times a year) but it was a brute to drive everyday and the added maintenance costs (3 gallon oil capacity) made me rethink. I bought an 04 Ram w/ Hemi and is does okay towing the same trailer but it is a lot better to drive everyday.

Wiegh all your options before buying. If it were me, I would have the diesel if towing all the time. If only towing occassionally go with the Hemi.
Good luck!!

 

I pulled 3 pairs of dozer tracks (6 tracks total) that weight about 3.5 tons with no problem, and I had to go about 80 miles up and down hills, corners. It was definatly not a straight road. I would recommend.

 

If towing were your main concern I would say no Dodge gas engines, period. The Diesel is good because of the gobs of torque you have available but the fact you don't have the 3rd only option and that useless tow/haul button ruined me on Dodges for heavy towing. My 03 Avalanche did much better on my 26' consession stand ( a box on wheels) but it was made to pull closer to it's power curve instead of letting it hunt all over for the correct gear. For occasional use, my 4.7 does fine up to about 45-50 mph pulling somewhere between 5000 to 6000 lbs. Once I got to that point, the hunt was on plus the wind resistance of my 26' travel trailer killed it as well. It was screaming up hill at 60 mph in 3rd gear sounding like she was going to blow! The 4:56 gear swap helped some but if I could go back in time, I would go diesel all the way - better mileage than gas, last longer and you always have the power when you need it.

 

I pull a 3600lb race car on the weekends plus weight of trailer, generator, tools , spare parts, tires...... I'm guessing 6500-7000 total. I have a 1500 QC Hemi with towing package 3.73 gears and 17" wheels. I have pulled this load through the mountains and on flat interstate, I do see some hunting but I just turn the tow/haul off when that happens and it does just fine. If you plan to drive this truck without towing more than 50% of the time I would say go with the Hemi for sure. If you will tow more than 50% of the time you need a deisel (remember Deisels are heavy and tend to get stuck unless they are 4x4 Even just on flat hard wet grass I have seen people have problems so theres more money up front) I like my truck and the only complaint I have is the fuel milage 13-14 in town 19-20 highway 10-13 towing.

 

I tow a 30ft toy hauler travel trailer with two Motorcycles on board. In the neighborhood of 6500 lbs, /absolutely no problem. I installed a volant cold air system. Mileage was greatly improved. The 1500 hemi has no problem at all towing this across 8 states from Maryland to Arkansas and back.
Chikez