We also have a 7.3 turbo version in our SD truck. When pulling some long hills with the larger trailer, the tranny would kick out of OD because the motor didn't have enough torque. Western PA and Eastern OH have many hills, and pulling in the lower gears was distracting.

I installed a Bully Dog adjustable programmer many years ago. It has variable settings, which allows the driver to select how much additional torque and HP he wants. These adjustments are made with a rotary dial on the dash, ranging from a mild trailer pulling increase to a full blown drag race setting. It also has an engine warm up idle speed, and a safety setting that restricts any large throttle usage for over eager parking attendants.

Part of the sales pitch of the programmers was an advertised mileage increase. Running empty I don't notice any mileage increase. However when pulling any of the medium trailers, I haven't noticed any mileage decreases, which typically ran about ~5 mpg less. When pulling the lighter trailers on level roads, I leave the setting off, which allows the original factory parameters.

When you are pulling hard and using the higher settings, you have to have an exhaust gas temp gauge. (pyrometer) The additional fuel added and the timing are altered to give you the large power boosting. In the higher ranges, prolonged pulling on hills, can exceed the recommended cylinder head temps and can ruin your engine. The lower setting, which allows our truck to remain in OD most of the time on the hills, is the setting that we commonly use, and over temping has never been a problem.

We are very pleased with the increased performance when we need it, and the ability to shut it off when we don't. The engine has remained completely reliable for many years. There are several companies that sell programmers for the 7.3. Compare their specifications, peruse the Internet truck sites and purchase a well known name brand. I doubt that you will be disappointed with the results.

I have a question. What is the maximum exhaust gas temp you like to see?Thanks

I don't like to encounter any readings over 1200 degrees under a sustained loading. Whilst climbing a long hill with a heavy load, I will sometimes let it climb to 1250 if the hill top is in sight. If not, I will select the OD "off" which reduces the torque loading on the engine. The other alternative is to temporarily select a lower HP setting of the programmer, which reduces the fuel flow, and lowers the EGT.

In several years, I've only had to do this a couple of times on very long, steep hills, during some hot summer days, when the rig was fully loaded with our larger trailer. In the "trailer" selected mode, this has never been necessary, only when using the more powerful settings on the very steep slopes.

Marla, also check out the Edge and Banks products. Here's some info on the BD chip I use:

http://www.xtremediesel.com/bullydog6position4-bankchip41613.aspx?gclid=CLrB7q-9q7wCFURnOgod9yIACA

I'm sorry, but I know nothing about that product or the applications for Cummins' diesels. Hogtownboss is our resident expert on upgrades and add ons for the Dodge trucks. Perhaps he will see this thread and offer some useful advise. 

There are various Cummins and Dodge truck forums that are a wealth of information. Make sure that the forum you are using for research, isn't sponsored by a supplier. The resulting threads often will advance the sponsors' products, whilst disregarding some comparable alternatives.

For whatever its worth -I had a 05 Dodge 1ton dually Cummins Diesel and added a BullyDog programmer to

the truck and only put it on the lowest setting - I think it was 49 HP increase - got another 4-5 mpg and increased the hp - great product then - on the open road would set cruise @ 75 mph and went over

Flagstaff Mtn on I-40 with out losing more than 3 mph towing a trailer combined weight loaded & trailer 17500 lbs.....made a good truck better....