6.5 GEP NA or 5.9 12v NA?

Steel Soldiers is supported by:

erasedhammer

Member
694
4
18
Location
Seattle
At a cross roads here.

I'm going to swap in a nv4500 either way, so I figured I have two options. I'm going with NA on both simply for reliability.

Obviously a 6.5 GEP is going to be drop in, probably cheaper... but I found a 5.9 12v complete engine for $800, 400k, but better than the $4k engines, and still within its lifespan.
I also don't have the space or tools to do much fabrication work. And I'm not exactly drowning in money...
I feel like a 5.9 could be a better long term investment, going to be keeping this truck for a long time.

For those that have done the 5.9 swap, what did it involve, and how much did it cost in the end?
 

simp5782

My safe word is Pork and Beans.
Supporting Vendor
8,439
968
113
Location
Memphis, TN
12v are not NA motors that came in trucks. Only equipment. They were pretty weak with their turbo compared to today standards. It would be like 100 to 130hp with out a turbo. You are going to pay for it in the cummins name for those little engines. 400k on an engine isnt bad if you are going to drive it every day or every other day. Letting a high mileage motor sit and drive it once a week will be prone to leaks other issues. Buy it for 800. Refresh it and be under 3k and be done with it
 

Barrman

Well-known member
4,399
50
48
Location
Giddings, Texas
The 6BT is over 1200 pounds fully dressed out. A 6.5 is about half that. Have some mercy on your front axle and kingpins.

$800 is a great price as mentioned in the post above. Buy it and flip it.

Also know that the NV4500 had a specific bellhousing for Dodge and a specific bellhousing for Chevy. Plus, I think there were some variation in the input shaft diameter between the 6BT version and all the other versions.
 

erasedhammer

Member
694
4
18
Location
Seattle
12v are not NA motors that came in trucks. Only equipment. They were pretty weak with their turbo compared to today standards. It would be like 100 to 130hp with out a turbo. You are going to pay for it in the cummins name for those little engines. 400k on an engine isnt bad if you are going to drive it every day or every other day. Letting a high mileage motor sit and drive it once a week will be prone to leaks other issues. Buy it for 800. Refresh it and be under 3k and be done with it
130hp doesn't sound bad..Same as 6.2. I don't care about speed. Just simplicity and reliability.

I'm seeing rebuilt kits for around 900-1000.
 

erasedhammer

Member
694
4
18
Location
Seattle
The 6BT is over 1200 pounds fully dressed out. A 6.5 is about half that. Have some mercy on your front axle and kingpins.

$800 is a great price as mentioned in the post above. Buy it and flip it.

Also know that the NV4500 had a specific bellhousing for Dodge and a specific bellhousing for Chevy. Plus, I think there were some variation in the input shaft diameter between the 6BT version and all the other versions.
GEP 6.5 is around 800 fully dressed.

Cant find a clear answer on the 12v, and it's not like I'm going to have all the accessories. Just an alt, water and PS pump.
 

simp5782

My safe word is Pork and Beans.
Supporting Vendor
8,439
968
113
Location
Memphis, TN
Around 1100 for a long block. And yes 130hp from a 12v would be high end on a NA with high Egts. More than likely it's a turbo 12 v. They were just non intercooled. so you could figure that out later for a little bit more power. But 100 to 130hp from a NA motor vs a 180 to 215hp turbo motor is night and day. Plus the 12v can get on upwards of 300 for a pretty reasonable price. Speed isnt a thing but it's nice to have it if you need it especially in a tin can
 

erasedhammer

Member
694
4
18
Location
Seattle
Around 1100 for a long block. And yes 130hp from a 12v would be high end on a NA with high Egts. More than likely it's a turbo 12 v. They were just non intercooled. so you could figure that out later for a little bit more power. But 100 to 130hp from a NA motor vs a 180 to 215hp turbo motor is night and day. Plus the 12v can get on upwards of 300 for a pretty reasonable price. Speed isnt a thing but it's nice to have it if you need it especially in a tin can
I'm not saying it is a na engine. I'm saying I'ma turn it into a na engine.
 

cucvmule

collector of stuff
Steel Soldiers Supporter
846
93
28
Location
Crystal City Mo
I would 6.5 the truck and keep it as simple as you can, cost. Take the 800 and freshen up some components.

To neuter a 5.9 when already not impressive when stock, is a step back in the power category. Put some cash into the 5.9 in a rebuild and find a Dodge to put it in. A tired 400k motor would be better if you major it and then you can maintain for another 500k.

There was a Man here putting a 292 gas into a CUCV that was a unique and interesting choice. I know that the 292 is a wise alternative for power and economy, plus an easier option to find compatible components.

Good Luck
 

erasedhammer

Member
694
4
18
Location
Seattle
I would 6.5 the truck and keep it as simple as you can, cost. Take the 800 and freshen up some components.

To neuter a 5.9 when already not impressive when stock, is a step back in the power category. Put some cash into the 5.9 in a rebuild and find a Dodge to put it in. A tired 400k motor would be better if you major it and then you can maintain for another 500k.

There was a Man here putting a 292 gas into a CUCV that was a unique and interesting choice. I know that the 292 is a wise alternative for power and economy, plus an easier option to find compatible components.

Good Luck

Personally I don't care about power at all.

6.5 Would be cheaper. Just comparing the two side by side, a 5.9 being an inline 6 is much simpler in design. But the conversion into a cucv would be costly.
 

sandcobra164

Well-known member
2,949
93
48
Location
Leesburg, GA
I think you've found your answer as to motive power. Now as to your statement of being limited on fabrication skills and budget makes me question why you want to put a manual transmission in. Do you have a currently running truck or is this a brainstorming session?
 

erasedhammer

Member
694
4
18
Location
Seattle
I think you've found your answer as to motive power. Now as to your statement of being limited on fabrication skills and budget makes me question why you want to put a manual transmission in. Do you have a currently running truck or is this a brainstorming session?
I do have a currently running truck. 6.2, th400.
Rusty as all ****, but low miles.

Im mostly brainstorming for now since I still have a little ways to go paying off the truck.
But my reason for a manual is really only because Ive had bad experiences with autos in military trucks. I just want something with extreme simplicity. As little moving parts and electronics as humanly possible.
 

cucvmule

collector of stuff
Steel Soldiers Supporter
846
93
28
Location
Crystal City Mo
Well it seems that in your quest for simplicity economics are not a factor, but that is one of your requests. Almost anything is possible with cash behind the endgame.

The CUCV is a simple economical truck to start with. So why make it complicated?

An 80hp at the rear wheels, na diesel for simplicity, not concerned about power but want a manual. I believe that you have answered your own question. Now you want affirmation?
 

erasedhammer

Member
694
4
18
Location
Seattle
Well it seems that in your quest for simplicity economics are not a factor, but that is one of your requests. Almost anything is possible with cash behind the endgame.

The CUCV is a simple economical truck to start with. So why make it complicated?

An 80hp at the rear wheels, na diesel for simplicity, not concerned about power but want a manual. I believe that you have answered your own question. Now you want affirmation?
I was mainly looking for information on a 5.9 swap in general.
Would've been better just to say it was going to stay turbo, I could've spent less time trying to defend my stance.
 

cucvmule

collector of stuff
Steel Soldiers Supporter
846
93
28
Location
Crystal City Mo
erasedhammer, honestly I like your idea. I believe that if you look around, maybe you tried already, do a search for the 5.9 you may find some good intel on
Steel Soldiers.

I have watched guy's at work do amazing things with the 5.9, but in Dodge Trucks, I surmise, to spend more time and bucks on a donor puller. They stay with the same chassis and use the money on repair or replacement on the 5.9 meltdown.

The reason I believe in the turbo is you can use low boost pressure and still be economical, and have some useable torque to move a 6,000lb truck smartly.
 

erasedhammer

Member
694
4
18
Location
Seattle
erasedhammer, honestly I like your idea. I believe that if you look around, maybe you tried already, do a search for the 5.9 you may find some good intel on
Steel Soldiers.

I have watched guy's at work do amazing things with the 5.9, but in Dodge Trucks, I surmise, to spend more time and bucks on a donor puller. They stay with the same chassis and use the money on repair or replacement on the 5.9 meltdown.

The reason I believe in the turbo is you can use low boost pressure and still be economical, and have some useable torque to move a 6,000lb truck smartly.
Just lost the engine that I was looking at so I guess I'll have to keep an eye on stuff for now. Focus on cleaning the truck up and see which engine will be cheaper.
 

NDT

Well-known member
Steel Soldiers Supporter
7,780
327
83
Location
Camp Wood/LC, TX
The 6.5 TD in my 2000 Chevy K3500 has more power than I know what to do with. It will pull 20,000 lbs up a long hill easy and spin tires if I jump on the throttle. I wouldn't dream of replacing it with a Cummins.
 

sandcobra164

Well-known member
2,949
93
48
Location
Leesburg, GA
I understand distrust of automatic transmissions yet as society evolves I only have 1 manual transmission vehicle in my fleet of personal vehicles. The CUCV you have has a TH-400 transmission which boasts many accolades of reliability. It is not a weak spot and the 6.2 would not likely upset it in your quest for an economical vehicle. It will upset you in this application because it is not an overdrive transmission and does not have the torque converter lock up function. Even so, you could easily expect 17 mpg combined out of a stock M1028 if you roll mostly highway.
 

dependable

Well-known member
1,598
50
48
Location
Tisbury, Massachusetts
The 5.9 is a tight fit in CUCV engine compartment, and will take some fabrication. In the one I've seen motor is shoehorned in at an odd angle and the valve cover still almost touches the firewall. The truck is loud and rattly as all get out too.

Don't get me wrong, I love my 6BT with NV4500, but it is in a '97 Dodge.
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks