[bart1212]

Ok so I'm looking at buying a 1997 dodge 12 valve cummins auto trans. I'm a gas guy don't know to much about diesel so I was curious I want to tow with this truck and also my daily so I want to have power for towing and going fast but I also want decent fuel economy and reliable am I asking to much? Appreciate any help on what I can do to achieve this

 

[badbart]

Ok so I'm looking at buying a 1997 dodge 12 valve cummins auto trans. I'm a gas guy don't know to much about diesel so I was curious I want to tow with this truck and also my daily so I want to have power for towing and going fast but I also want decent fuel economy and reliable am I asking to much? Appreciate any help on what I can do to achieve this

Welcome to the site. The old Cummins is a reliable workhorse. It will pull very well. The transmission is the weak point but that can be addressed. How much weight are you planning on towing? You mentioned "towing and going fast". Those two words should never be used in the same sentence when you're talking about old diesels. You can tow or you can go fast. But not both. Those old Cummins can make some serious power with a bit of tweaking. My cousin put a 5.9 in a Ford Ranger. His is putting out 1800 ft./lbs. of torque! He can smoke the tires at 70 mph!

 

[bart1212]

You are right about that and I guess I miss spoke I'm not looking to go muchover if at all 100 I just know my old man has a 02 f350 7.3 that you don't want to do 80 for a long period of time due to the high rpms with a 4:10 gear ratio but back to the cummins I'll be towing about 15,000. I am aware of the transmission problem that will probably be my first thing to do. I have seen power packs from banks that claim to give and additional 127hp and 311ft of torque sounds good to me but at about 3k can't quite afford that right now I am 18 and just got my first construction job so it will be a little bit. But I'm definitely willing to spend some money I know you can go as fast as you want it just depends on how much money you have haha

 

[nevrenufhp]

There's so many free, and cheap mods for a 12 valve, your head will spin. The power pack is a big expense for little gain. For $3k you can double factory hp. The trans will be the issue no matter what. There's 3 transmission options: 1,get a built one. 2, build your own from Transmissioncenter(videos included). Very good learning experience! 3, swap to a manual trans.
For towing, I'd suggest the freebie pump mods, good injectors, head studs, compound turbos(depending on how big the injectors are), and a manual trans with xtra cooler. Then, the easy stuff: synthetic fluids on all drive train parts.

 

[bugman]

You are right about that and I guess I miss spoke I'm not looking to go muchover if at all 100 I just know my old man has a 02 f350 7.3 that you don't want to do 80 for a long period of time due to the high rpms with a 4:10 gear ratio

On that old 7.3, it will do 80 mph all day long with 4:10's. I do it all the time with no problems at all.

 

[badbart]

On that old 7.3, it will do 80 mph all day long with 4:10's. I do it all the time with no problems at all.

At the expense of fuel mileage. I set the cruise on 72 one time and I got 12 mpg. I have gotten 20.7 mpg at 55 mph.

 

[bugman]

At the expense of fuel mileage. I set the cruise on 72 one time and I got 12 mpg. I have gotten 20.7 mpg at 55 mph.

I have gotten as high as 22mpg driving 75-80 for both tanks all freeway driving, hand calculated but usually it is close to 18mpg at 80 and summer time fuel. Last trip from my home to Denver and back 340 miles with city driving I got 19mpg.

My truck may be the exception instead of the rule on mileage.