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I've decided to do a Cummin's conversion

FellowTraveler

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Sorry, I've been remiss in posting updates and images....so....
Heater hoses to front/rear cores & troque converter heat exchanger are all MIL-SPEC silicone w/wrapped UV-OZONE barrier, the fan to radiator gap was increased using 1st gen Cummins pulley & attached to a 3rd gen hub bracket.
I'm rewiring for one battery.
The GM shifter cable looped from front of engine bay and modified 4L80 cable bracket are used w/Dodge linkage which shift pattern operating opposite GM's it shifts & operates nice and smooth.
Bottom image is lower radiator hose and Cummins charge air cooler (CAC) fit nice and clean looks factory too. DSCI0004.JPG DSCI0002.JPG DSCI0002.JPG DSCI0004.JPG DSCI0006.JPG DSCI0003.JPG DSCI0007.JPG DSCI0005.JPG
 

FellowTraveler

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I have both of my large B&M Hy Tek fin/plate coolers w/fans ready for mounting between the front chassis rails from the 1st x-member to the tailing edge of the front bumper.....waiting on AN-8 hose fittings for the SS braided Teflon hose and I will be using the newer gen. Ram Cummins torque converter plate cooler too.
DSCI0001.JPG DSCI0002.JPG
 

FellowTraveler

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Made some more head way with my conversion.

I installed a Teflon bushing on the shift cable at the shift lever.

Have the front transmission coolers assembled w/8-AN fittings using 500 degree F capacity Teflon braided hose from transmission to heat exchanger then to front coolers then Nylon SS 350 degree F capacity braided lines connecting coolers then back to hard line return to transmission.

DSCI0001.JPG DSCI0003.JPG
 
Last edited:

n8in8or

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Made some more head way with my conversion.

I installed a Teflon bushing on the shift cable at the shift lever.

Have the front transmission coolers assembled w/8-AN fittings using 500 degree F capacity Teflon braided hose from transmission to heat exchanger then to front coolers then Nylon SS 350 degree F capacity braided lines connecting coolers then back to hard line return to transmission.

View attachment 54304 View attachment 54305
That cooler setup looks neat and tidy. Nice.
 

FellowTraveler

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Looks like your tranny fluid will return barely lukewarm no matter how hard you work it! Nice! I noticed you have them plumbed in series vs parallel, good call. You get better temperature drop that way.
Thanks, I had put lot's of costy upgrades into the 47RH transmission and want to protect it as much as I can. OH and it was my first 47RH build too I was taken back by how easy it all was however, I had spent the most hours ever on any transmission with the valve body mods alone.
 

FellowTraveler

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If you decide you want to run a smaller trans cooler for space saving's, the earl's super cooler's are alot more efficient than those b&m coolers. I saw a significant drop in temps going from a b&m to the earls cooler.
Remember which models?
'These only have 3/16" gap at the chassis rails so real tight, I wonder why the Earls run cooler as the B&M's are fin/plate design?'
 

THEFERMANATOR

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Remember which models?
'These only have 3/16" gap at the chassis rails so real tight, I wonder why the Earls run cooler as the B&M's are fin/plate design?'
I believe it was the 82510erl that I installed. The b&m cooler I found had horrible flow. The 1st 2 inches on the side of the fittings got hot, by the time you got to the other end it would be barely warm to the touch with trans temps at 190 degrees. The earl's cooler is built just like setrab coolers which are very high end coolers. It's a stacked plate deaign where the fluid runs across the entire width of the stacked plate instead of just through the little capilary passages like the b&m cooler does. I went with the b&m at 1st because I figured a stacked plate was a stacked plate, and the b&m cooler was a long made cooler just like GM used oem. But I had to switch to the earl's to keep trans temps in check because of how poor the airflow is through the gmt-400 grill.

https://www.summitracing.com/parts/ear-82510erl
 

FellowTraveler

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I believe it was the 82510erl that I installed. The b&m cooler I found had horrible flow. The 1st 2 inches on the side of the fittings got hot, by the time you got to the other end it would be barely warm to the touch with trans temps at 190 degrees. The earl's cooler is built just like setrab coolers which are very high end coolers. It's a stacked plate deaign where the fluid runs across the entire width of the stacked plate instead of just through the little capilary passages like the b&m cooler does. I went with the b&m at 1st because I figured a stacked plate was a stacked plate, and the b&m cooler was a long made cooler just like GM used oem. But I had to switch to the earl's to keep trans temps in check because of how poor the airflow is through the gmt-400 grill.

https://www.summitracing.com/parts/ear-82510erl
Interesting, it seems you had a B&M LONG 'low pressure drop' (LPD) cooler that didn't work correctly I had the same type of problem with a large LONG LPD cooler myself and "no the manufacturer didn't stand by the product."

As the aux coolers go worst to best performance are tube/fin, plate, then plate/fin which are supposed to be so efficient the size can be reduced in most applications.

Truthfully I was more worried about the 3rd gen Ram Cummins torque converter heat exchanger 'failure rate' until I read this.

I'll be monitoring these non-LPD B&M coolers "just in case" and if I have the same issue then it will be corrected using what you suggest.

Aa always "thanks for your input."
 

FellowTraveler

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I had just noticed that I had posted images of my GM shift cable attached to the top of the Dodge shift lever which worked fine however; I found attaching the cable under the shift lever and using a Teflon bushing it made shifting super smooth and more inline with cable assembly.
 

FellowTraveler

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Well, I found that a few have done their Cummins into GMT400 conversions on the K1500 platform Suburban’s using the 47RH w/NP243c t-case horizontal and keeping the IFS w/o any lift and it’s been running that way for 100k+- w/o issues.

One conversion over at 4BT conversions was done by a master tech teaching automotive tech at the college level for 33 years.
He used a 2”x4” ¼” thick tube 48” tube welded 12” each side to the back of the t-bar x-member then cut out the center section of the factory t-bar x-member to within 1” of each key bracket then boxed everything, this gave clearance needed to use the longer Ram Cummins 47RH 4x4 O/D extension w/GM t-case.

His vehicle has no body or suspension lift whatsoever however; he did have to hammer the rear floor area up above the t-case, my floor looks like it would require cutting and fabrication in that area to clear the t-case which is no big deal.

Perhaps, his Cummins is not mounted as far back as mine I just don’t know but my concern is any moving of the t-bar x-member back from its factory position could be a problem ‘he says no’ and thinking I may be able to perhaps space the steel tube away from the t-bar x-member to keep the factory mounting point of the t-bar x-member.

Another modification he used was too remove the rivets from the x-member just behind the t-bar x-member and refasten with grade 8 fasteners this makes the install doable and for later R&R of the Ram Cummins drivetrain if the need were to arise.
I’m looking for input pro or con.
 

n8in8or

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Well, I found that a few have done their Cummins into GMT400 conversions on the K1500 platform Suburban’s using the 47RH w/NP243c t-case horizontal and keeping the IFS w/o any lift and it’s been running that way for 100k+- w/o issues.

One conversion over at 4BT conversions was done by a master tech teaching automotive tech at the college level for 33 years.
He used a 2”x4” ¼” thick tube 48” tube welded 12” each side to the back of the t-bar x-member then cut out the center section of the factory t-bar x-member to within 1” of each key bracket then boxed everything, this gave clearance needed to use the longer Ram Cummins 47RH 4x4 O/D extension w/GM t-case.

His vehicle has no body or suspension lift whatsoever however; he did have to hammer the rear floor area up above the t-case, my floor looks like it would require cutting and fabrication in that area to clear the t-case which is no big deal.

Perhaps, his Cummins is not mounted as far back as mine I just don’t know but my concern is any moving of the t-bar x-member back from its factory position could be a problem ‘he says no’ and thinking I may be able to perhaps space the steel tube away from the t-bar x-member to keep the factory mounting point of the t-bar x-member.

Another modification he used was too remove the rivets from the x-member just behind the t-bar x-member and refasten with grade 8 fasteners this makes the install doable and for later R&R of the Ram Cummins drivetrain if the need were to arise.
I’m looking for input pro or con.
From the outside looking in, this seems like it has more pros than cons.

Pros: I imagine it would keep your center of gravity lower because I'm guessing you'd have to lift the truck a bit to clear a straight axle. The other pro I'm guessing is ride quality - keeping the factory IFS will probably ride a bit better than a leaf sprung solid axle. Now I don't know if those are concerns of yours or not, but they would be factors if I was considering this. I like that the rivets would be swapped with bolts for serviceability -that's smart.

Cons: Wow factor - an SAS Sub would look really cool and intimidating. The Dana 60 has a known track record of durability. I think the SAS will be more fabrication time than the crossmember modification, but I could be wrong....maybe a wash?
 
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