2nd on the partsmike. I make my own rods and bought the TRE's from him. Lots of good info on the site.
Builds Building a Tow Rig (1 Viewer)
- Thread starter D'Animal
- Start date
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Very nice truck to make into a tow rig!!
I have done a few Cummins conversions, and in general do a lot of diesel work. Currently I am doing a Cummins 4bt into a Jeep TJ.
The first suggestion I would make is lose the fan and clutch to gain the 4" you need. For empty daily driving you will not need it. You can always add an electric fan in front of the rad with a thermostat switch. But I doubt you will need it very much. Secondly your gearing is way off. On that engine for best economy you want to stay below 2000rpm. The torque sweet spot is 1800-2200. Your 4.56 gears will put you at over 3300 @75mph. You really need 3.50-3.73 gears with your 35" tires to keep the engine at it's torque peak for towing. My service truck is a first gen Dodge with 727, the body is a box truck and it weighs 16,000#, it still has the 3.07 gears. No it is no hot rod but it will get out of its own way. BTW yes the fan is gone, took it off for a dyno run and it never got put back on.
Make sure you put EGT and Boost gages in there to keep track of how hard the engine is working, especially since I think you said the pump is turned up.
I have done a few Cummins conversions, and in general do a lot of diesel work. Currently I am doing a Cummins 4bt into a Jeep TJ.
The first suggestion I would make is lose the fan and clutch to gain the 4" you need. For empty daily driving you will not need it. You can always add an electric fan in front of the rad with a thermostat switch. But I doubt you will need it very much. Secondly your gearing is way off. On that engine for best economy you want to stay below 2000rpm. The torque sweet spot is 1800-2200. Your 4.56 gears will put you at over 3300 @75mph. You really need 3.50-3.73 gears with your 35" tires to keep the engine at it's torque peak for towing. My service truck is a first gen Dodge with 727, the body is a box truck and it weighs 16,000#, it still has the 3.07 gears. No it is no hot rod but it will get out of its own way. BTW yes the fan is gone, took it off for a dyno run and it never got put back on.
Make sure you put EGT and Boost gages in there to keep track of how hard the engine is working, especially since I think you said the pump is turned up.
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- Thread starter
- #63
On my '97 Dodge I just threw in 4.11s from the stock 3.54s. I have 33s and am looking to go 35s just to bring the RPMs down a bit on the freeway. With the 3.54s, I was around 1700 RPM @ 60 in 4th going up the 4 lanes. With the 4.10s I am about 2200 in 4th also up the 4 lanes. I prefer the 4.10s a lot more as I am in the motors "happy" range and I can vary speed up and down quite a bit before the HX55 lags.
I do not know your exact O.D. ratio but using a general O.D. ratio of 0.78:1 the 4.11 gears and 35" tires should put you at 2050 rpm @65mph, or 2370rpm @75mph.
fj40charles
SILVER Star
Are you running a stock HX55? That is a large turbo to spool up.
How much are you fueling with the P7100 pump?
HX55 is too large for an 8.3L.
4.10 will be fine for a tow rig. Sure the RPM might not be optimum for a freeway flyer but 55mph is max legal towing speed and with 35's you'll be in the sweet spot.
4.10 will be fine for a tow rig. Sure the RPM might not be optimum for a freeway flyer but 55mph is max legal towing speed and with 35's you'll be in the sweet spot.
Dodge manual O.D. is .74 and auto is .69 .
- Thread starter
- #70
I had the Dana 60 rebuild with 4:11's and installed a posi lock. New brake calipers, U-joints in the axle shafts, rotors turned and a new set of lockers. They shop that did the work really treated me fair but dang did that price add up.
I removed the old axle assembly and installed the new one last night. I forgot to order new U-bolts and studs so it is jsut sitting on the axle for now.
The steering is all hooked up, the fuel lines are ran, etc. I should be driving it around the yard by the weekend.
I removed the old axle assembly and installed the new one last night. I forgot to order new U-bolts and studs so it is jsut sitting on the axle for now.
The steering is all hooked up, the fuel lines are ran, etc. I should be driving it around the yard by the weekend.
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- Thread starter
- #71
Finished bolting the front axle under it tonight.
I fabbed up the Brake booster bracket to the Dodge Brake booster. I had to extend it 1 3/4" and now the brake lines are not long enough. The booster pushrod has a large hole and the lever off the pedal has a small hole. I have to get a bushing to mate them up.
I bolted up the tie rod but lost one of the nuts.
Clutch pedal is installed. Next step is to cut the firewall and install the Chrysler Clutch master Cylinder mount.
The radiator support is fabbed up for the radiator but I have not installed it yet. I have to put the four headlight set up on it after I remove the two headlight setup.
I fabbed up the Brake booster bracket to the Dodge Brake booster. I had to extend it 1 3/4" and now the brake lines are not long enough. The booster pushrod has a large hole and the lever off the pedal has a small hole. I have to get a bushing to mate them up.
I bolted up the tie rod but lost one of the nuts.
Clutch pedal is installed. Next step is to cut the firewall and install the Chrysler Clutch master Cylinder mount.
The radiator support is fabbed up for the radiator but I have not installed it yet. I have to put the four headlight set up on it after I remove the two headlight setup.
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- Thread starter
- #72
The radiator support is fabbed up for the radiator but I have not installed it yet.
I have to put the four headlight set up on it after I remove the two headlight setup.
I have to put the four headlight set up on it after I remove the two headlight setup.
- Thread starter
- #73
Here is what it kinda looks like now.
- Thread starter
- #74
Scrap.
- Thread starter
- #75
Tonights project almost done!
- Thread starter
- #76
Here is the clearance I have at the rear of the engine. I can still remove the back valve cover.
Beverage container is for size reference only.
Beverage container is for size reference only.
fj40charles
SILVER Star
Looking good Dan!
- Thread starter
- #78
Thanks
Being home only on the weekends and splitting my time between three builds and doing ranch chores stretches me thin.
Everything on this is a custom build. No parts catlogs are avaliable to order crap from. That could go for the other two projects as well.
Dan you have a PM on that intercooler. Ya know with a little mod to the pushrod linkage between the pedal and the booster, the 77 and earlier GM booster and bracket will work on the 72 and down firewall. It would put it closer to the firewall. BTW that intercooler will fit between the radiator and the grille on the outside of the core support.
- Thread starter
- #80
