Cummins Swap questions:
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Elder User
Joined: Jul 2001
Posts: 581
Likes: 2
From: Milton, Wa
Cummins Swap questions:
Hello all. I've got a '78 F250 Crew, 4x4, with 4.10s and it's a longbed conversion (person who "restored" it lengthened out the frame)
I've been doing quite a bit of reading lately on this. Have been keeping a powerpoint file on everything, tips, pics of mounts, crossmember mods, & other stuff.
I've got a couple questions that I've read a little on but not enough to satisfy my question:
1) I have a '93 3/4 ton 4x4, Auto. Besides the motor & trans I was planning on using the t-case & front & rear axles. With my frame, is it feasible to use the axles from the Dodge? Or is the spring-to-spring measurements all wrong? I obviously don't mind moving spring perches & shock mounts.
2) Fuel tanks. Let's say I'm only going to use the saddle tank. How do I go about hooking up the return fuel line? And is there going to be an issue with fuel starvation if I get down to a low level (say 1/4 tank)?
I think that's about it for now. I'm sure there will be more. The plan is to do most of the fabrication pieces of the swap during my 2 weeks off around Christmas. I'm hoping/planning for a 2 month downtime We'll see if I succeed.
Here's the rig I'm putting it in:
Ryan
I've been doing quite a bit of reading lately on this. Have been keeping a powerpoint file on everything, tips, pics of mounts, crossmember mods, & other stuff.
I've got a couple questions that I've read a little on but not enough to satisfy my question:
1) I have a '93 3/4 ton 4x4, Auto. Besides the motor & trans I was planning on using the t-case & front & rear axles. With my frame, is it feasible to use the axles from the Dodge? Or is the spring-to-spring measurements all wrong? I obviously don't mind moving spring perches & shock mounts.
2) Fuel tanks. Let's say I'm only going to use the saddle tank. How do I go about hooking up the return fuel line? And is there going to be an issue with fuel starvation if I get down to a low level (say 1/4 tank)?
I think that's about it for now. I'm sure there will be more. The plan is to do most of the fabrication pieces of the swap during my 2 weeks off around Christmas. I'm hoping/planning for a 2 month downtime We'll see if I succeed.
Here's the rig I'm putting it in:
Ryan
Mountain Pass
Joined: Sep 2008
Posts: 191
Likes: 1
Conversion
I think with your wheel base you may be able to retain the saddle tank. I had to remove mine and use only rear tank since the Dodge 518 trans was longer than the C6. I left the Ford axles and bought an Advance Adapter to keep the Ford style 205. I think there is a factory return line for fuel that can be utilized.
Cargo Master
Joined: Oct 2010
Posts: 3,417
Likes: 32
The sping perch measurements are different enough to be a pain to swap them. The rear you could cut the perches off and re weld them in the proper spot. I am running a gm 14 bolt that I did that to.
As far as your tank goes I highly recommend you hook up a sump to keep from sucking air. I had to do that with my tank because I would suck air and loose fuel pressure in left hand turns.
As far as your tank goes I highly recommend you hook up a sump to keep from sucking air. I had to do that with my tank because I would suck air and loose fuel pressure in left hand turns.
Senior User
Joined: Sep 2014
Posts: 162
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From: Bay St. Louis, MS.
I'm in the process of installing a 5.4L gas burner in my 78 F150. I needed a return fuel line and an elect fuel pump so I bought a rear tank for a 1996 F150. The 96 F150 was fuel injected and I have it powering up now. Haven't fueled it up yet but I expect it to work just fine.
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Elder User
Joined: Jul 2001
Posts: 581
Likes: 2
From: Milton, Wa
I think I've decided to go with a second generation and use the dodge t-case. Any issues with fitment of the Dodge t-case inside the frame? For the rear axle, I'm thinking I'll use the Dodge axle so I have the right gear ratio and can at least drive it while I save up for gears for the front.
Thanks.
Cargo Master
Joined: Oct 2010
Posts: 3,417
Likes: 32
I ended up selling the '93 I had. Made some decent coin on it I think I've decided to go with a second generation and use the dodge t-case. Any issues with fitment of the Dodge t-case inside the frame?
For the rear axle, I'm thinking I'll use the Dodge axle so I have the right gear ratio and can at least drive it while I save up for gears for the front.
What do you mean by "hook up a sump"?
Thanks.
I think I've decided to go with a second generation and use the dodge t-case. Any issues with fitment of the Dodge t-case inside the frame? For the rear axle, I'm thinking I'll use the Dodge axle so I have the right gear ratio and can at least drive it while I save up for gears for the front.
What do you mean by "hook up a sump"?
Thanks.
I ended up using this as a fuel sump.
Beans Diesel Sump
I would've welded one into my tank but it had already had fuel in it.
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Elder User
Joined: Jul 2001
Posts: 581
Likes: 2
From: Milton, Wa
If you don't have a fuel sump you will possibly have issues when your fuel is low making turns or stopping. Your suction straw can draw air and you will loose fuel pressure.
I ended up using this as a fuel sump.
Beans Diesel Sump
I would've welded one into my tank but it had already had fuel in it.
I ended up using this as a fuel sump.
Beans Diesel Sump
I would've welded one into my tank but it had already had fuel in it.
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More Turbo
Joined: Apr 2007
Posts: 656
Likes: 5
From: Salisbury, PA
What ever you do DO NOT use a stock metal fuel tank. Things will be fine for a while and then all of a sudden your injection pump will be junk. I went through 3 of them before I found out my stock gas tank was the problem. I did some reading on line and read that diesel fuel will eat the coating inside the old fuel tank which will then lead to rusting and very very fine metal/rust powder will get through your fuel filter and ruin your injection pump. Put a plastic tank in. I never had a problem since.
The 2nd gen chain drive transfer case fits between the frame with no issues. I made my own cross member when I did my 2nd gen Cummins swap with NV4500 and NP241 transfer case.
The 2nd gen chain drive transfer case fits between the frame with no issues. I made my own cross member when I did my 2nd gen Cummins swap with NV4500 and NP241 transfer case.
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Thread Starter
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Elder User
Joined: Jul 2001
Posts: 581
Likes: 2
From: Milton, Wa
What ever you do DO NOT use a stock metal fuel tank. Things will be fine for a while and then all of a sudden your injection pump will be junk. I went through 3 of them before I found out my stock gas tank was the problem. I did some reading on line and read that diesel fuel will eat the coating inside the old fuel tank which will then lead to rusting and very very fine metal/rust powder will get through your fuel filter and ruin your injection pump. Put a plastic tank in. I never had a problem since.
The 2nd gen chain drive transfer case fits between the frame with no issues. I made my own cross member when I did my 2nd gen Cummins swap with NV4500 and NP241 transfer case.
The 2nd gen chain drive transfer case fits between the frame with no issues. I made my own cross member when I did my 2nd gen Cummins swap with NV4500 and NP241 transfer case.
Cargo Master
Joined: May 2011
Posts: 2,387
Likes: 138
From: Northern California
I found this website when reading 4 Wheeler Magazine... Not sure where they are on prices but they seem to offer a comprehensive selection of adapters and such for the cummins diesel to all sorts of transmissions. Thought you all might find it useful.
1967-1979 Ford F-Series | Diesel Conversion Specialists
1967-1979 Ford F-Series | Diesel Conversion Specialists
Cargo Master
Joined: Oct 2010
Posts: 3,417
Likes: 32
I found this website when reading 4 Wheeler Magazine... Not sure where they are on prices but they seem to offer a comprehensive selection of adapters and such for the cummins diesel to all sorts of transmissions. Thought you all might find it useful.
1967-1979 Ford F-Series | Diesel Conversion Specialists
1967-1979 Ford F-Series | Diesel Conversion Specialists
Cargo Master
Joined: May 2011
Posts: 2,387
Likes: 138
From: Northern California
I guess that is good to consider. It would be interesting to see the process in which they make their templates though. With the right sized mill and know how, much of the stuff would be easy enough to carve out of a piece of aluminum or even cold rolled steel if so desired.
Posting Guru
Joined: Dec 2012
Posts: 1,722
Likes: 7
From: Shelton, Wa
You can get factory replacement poly tanks
Just Gas Tanks is your complete online shop for IMS, Clarke, Acerbis, and Safari Fuel Tanks. - Just Gas Tanks.com
Just Gas Tanks is your complete online shop for IMS, Clarke, Acerbis, and Safari Fuel Tanks. - Just Gas Tanks.com
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