GMC 6.5 TD vs Dodge Cummins Dilema

[jdmetcalf57]

I have a '99 K3500 4wd crew cab dually with an automatic transmision. I love the crew cab but 2 of my 3 kids moved out and I don't really have to have the crew cab anymore. I hate the auto trans to pull with and don't really like the duals. It wouldn't be too much trouble to change to SRW but would be a major chore to change the tranny to manual and fairly expensive. If I had a manual and SRW I would not consider trading it.

However the truck is still worth about $16K and I could trade it for a Dodge Cummins 2500 4wd (probably 12V) manual for not much money difference. I am considering this. I should also gain some fuel economy and I don't think you can beat a Cummins for reliability.

I would appreciate anyones opinions on this. I need to do something soon.

[jspringator]

Sounds like you know what you want to do! Just check out the new one carefully. Sometimes the devil you know...

[jbell]

The 12v p7100 pump motor is the best of the lot if you like to tinker with HP. It's what banks used for their world speed record run truck. 80psi boost -- wow.

[Keith Richards]

Chevy seems to be a better allaround truck,dodge seems to have the better motor.I know a dually can be cumbersome,I had to get rid of mine because of that.Just weigh out the options,and good luck.I cant remember if you said the dodge was a manual ,but the automatics arent known to be great.

[damork]

It appears that a tranny from www.dieseltrans.com (http://www.dieseltrans.com) is what you need if you have an auto behind a Cummins in a Dodge. I was considering going that route when I was having all sorts of stalling problems in my 6.5. The 12V engines can really be cranked up. Some 24V engines with the electronic pumps had lift pump problems that if not caught soon enough would destroy the main pump.

[DChristie]

Greetings from the swamp!

I had a '98 12v Ram 2500 4x4 w/auto, I traded it for the '95 chevy in order to reduce my overall debt. I'm glad to be debt free, but I miss my Dodge. The only downside/issue with was the weight of the engine. I had to drive off road for work some-times and that Cummins was like a fat woman in high heels walking across a freshly watered lawn, I put it on the pan several times before I could do anything about it. The 4x didn't help. I became an excellent judge of turf conditions! If I had doubts I'd walk it first.
Other than that there was a regularly (20K?) scheduled adjustment to the trans bands that I learned how to do my self, the auto always felt weird but never gave me any trouble. Never got to try a manual.
When I can Pay cash for a Dodge I'll go back, but I want the 24v. Seat of the pants difference in perfomance. The 12v is bulletproof though.

Good luck

[Diesel Dan]

I went the other way. Traded in a '93 GMC EXT cab turbo diesel on the '98 12V quad cab. Had several crewcabs in the past, but wanted a cummins. We figured the kids(2) would be ok for short towing trips in the back.

Unfortunately there is less room in the back of the '98 than the '93 that I traded in. The don't matter now, 4 days after I bought the dodge a lady ran a stop sign and hit me in the RR tire. Spun the truck around and rolled into the ditch, totalled :mad: . There's one rare 12v/quad cab down the drain.

Well in that short time we really regretted not getting a GM crewcab. For interior room only. I bought the dodge back from the insurance company and sawzalled the roof off, installed a cage and vinyl top, play/work truck now. The trans doesn't shift how I'd like it but hasn't failed, I do a lot of manual shifting. However both of my 4L80Es have required fixing, converter in the '00 and 4th gear overrunning clutch/drum on the '91(1998 GM SRTA trans).

Being that you want a manual trans and only 1 person for the back then I think you should go for it. $300 will wake a 12v right up. 3GSK for increased RPM range and new fuel plate.

In stock form the dodge(420 TQ) had more grunt down low than my 6.5(430). The 6.5 would have been faster in a drag race but....

[jdmetcalf57]

Thanks for the input guys.

I have been looking real hard but I will not buy a dodge auto and the manual shifter set up on the latter models really waste a lot of foot room for the front middle person. I am really having a hard time swallowing the very limited room that the dodges have.

I am going today to check out a cummins conversion on a mid 90's chevy. I am leaning toward the idea of keeping my truck, spending the $1500 or so that it would take to convert it to a manual and possibly putting a cummins in it when the 6.5 dies. Just can't get what I want.

My ideal truck would be a chevy crew cab, 4wd, srw, manual trans with cummins engine. Oh and by the way it wouldn't cost more than $14000, get 30mpg and last 500k miles.

I might just make this a project truck and work on it. I can get a cummins engine for around $4-5k. I used to have this truck minus the cummins (it had a 350 gas, mileage stunk)and was stupid and traded it for the auto drw that I have now.

[JeepSJ]

JD - that is basically the same setup that I want to get into, but I want a dually - I'd like the extra capacity for a cab over camper and towing my CJ.

[surfbeetle]

My dodge Cummins has 132000 miles and just goes and goes and goes. Only have been stranded twice in 10 years when the batteries went dead.
My 6.5 suburban has 130000 miles, has needed a new alternator and 6 injection pumps in 7 years.

[moedog]

AUTOWORLD IN MONTANA IS AN EXPERT AT CUMMINS CONVERSIONS INTO ANYTHING YOU WANT. DONE OVER 300 OF THEM. HAVIND A 97 CUMMINS, 5SD MANUEL AND AN UNDER-OVERDRIVE INSTALLED IN MY 97 CC NEXT SPRING. CANT WAIT!!!!

[jbell]

http://www.fordcummins.com/images/rodcomparison.jpg Here's guys that do cummins repowers.... This pic shows why.....

[jdmetcalf57]

I think I've finally made my mind up after looking for a Dodge 4wd manual trans extednded cab '94-2001 for several months. I'm going to keep my K3500 Crew cab.

Yeah I know you can't beat the cummins and I may put one in my truck someday but Dodge must only hire little people. Their extended cab would require midgets to ride there and their new so-called crew cabs need midgets to fit comfortabley there also.

This set up in a dodge must not have been very popular with new truck buyers but is extremely hot for used truck buyers. I have yet to see one for sale for more that a couple of days and they sell at dealers for several thousand more than Kelly or NADA appraised them at. The last one I called about showed up on Autotrader.com and the second day it was bought by an individual that lived 6hrs away. As usual I'm a day late and a dollar short.

I am quite satisfied with my K3500 6.5TD's stock power. However I am always looking for ways to increase fuel economy. I'm hoping that the 6.5 will run at least 250k miles. I've been told by a rebuilder that that is when he starts seeing them need work. Some people have many hundreds of thousands of miles on the Cummins but the Cummins web site says the ISB6 averages 350K miles between overhauls.

Given this decision I guess my truck is in for some serious changes. Auto trans to manual and DRW to SRW and lots of gages for every function I can think of. EGT, boost, fuel pressure, turbo back pressure, vacuum, and probably throttle position. Hopefully all of this will help me squeeze a few more mpg.