The Stovebolt Site Forums The Shop Area The HiPo Shop 6.6L Duramax into 65 K20

i recently purchased a 1965 K20 with the intentions of putting a 6.6L Duramax, ZF S6-650 transmission and mathcing transfer case, 14 bolt chevy full float rear and front dana 60 with 3.73 gearing into it. i was just wondering if anyone had done that already or anything like it? maybe they could give me some heads up about what this project is going to involve. i will be starting this project in one month when i return home from iraq. thanks so much
Jonathan

That will make a great truck. I've never done it but there has been some posts on it before on this website. It seems the bigest problem is the electronic engine controls. One poster said there is a harness available for that.

ok thank you very much. i hope to start very soon after returning home in august. i will try to put progress pics on here when i figure out how later on. thanks
Jonathan

Sounds like an interesting project!

Have you found www.4btswaps.com yet? it's a forum for diesel engine swaps of all kinds, and a great resource for tips, ideas, and answers while researching or performing a diesel swap.

Don't have any experience with the duramax, but as with any engine swap and restoration be prepared to spend some money. Even if you do all the work yourself the parts add up pretty quick.

I'm about 5 years into my swap now, buying parts and working on it as time and money allows.

Keep up updated on your project and progress,

Grigg

thank you so much! i will check that out. i have saved up somewhere in the ballpark figure of 12000 dollars and i already have the truck and i fully capable shop with a staff who is there to help with questions and such. it is an auto skills shop on an air force base that i have access to with my military status. i also have two months when i return home before i have to go back to work. so i am thinking i can spend four or five days a week working on this truck and with my lump sum of funding i can have it driveable in a month and a half or so. all i will be doing is working on this truck. no job yet, no school, so i should be able to make some killer progress granted i can find all the parts. thanks again.
Jonathan

Great!
Sounds like you already have a plan and you've probably already thought of these things.
Please fill us in on some more of the details, and we love pictures.

Do you already have the engine and transmission?
Have you figured out electrically how to run the duramax without the original truck wrapped around it? There are a few wiring choices/kits out now.
What shape is the 65 truck in to start with, do you need to do much restoration work to it as you also swap the engine and transmission?
Do you have plans to upgrade the brakes to match the power and possible speed the new engine will give you?

How will the truck be used, and what rear axle gears and tire size do you have planned?
Gearing is possibly the single most important part of a diesel engine swap. I've driven a few diesel conversions with poor (slow) gearing, then the same trucks with gears matched to the intended use, the difference is like night and day.

Grigg

I like this idea. Of course its because I'm putting a cummins 6bt +NV4500 and 3.73:1 in a 65 one ton. BTW thanks for you service and look forward to a safe return! Dave

alright lets see if i can answer all these questions. very very good questions lol. ok

1. no i do not have the engine and tranny as i havent been home to check them out first but i have found a few places to purchase them. i am going to get a fairly high mileage engine that is $4000 or less. my uncle is a professional diesel mechanic so any rebuilding neeing done he can teach me. the tranny i have found on two sites and it is a little costly but it is an awesome tranny and you get what you pay for most of the time.

2. no i havent looked at the wiring harness cause i dont know enough abot wiring engine control( especially on a diesel) that i wouldnt know what is good or not. when i get home i am gonna make up a detailed build plan and have the guys at the shop and the bolters help me find the parts i need.

3. the K20 body is in amazing shape. there is one rusted out piece under the drivers door and i 10" hole in the floor board. other than that there is no major defect with the body. and it has factory A/C which i think is amazing!!!!!!!!!!

4. brakes. yes i am gonna get a disc brake conversion for the rear brakes and get the largest cross drilled rotors i can put in my 18" rims. the truck already has a brake booster in it but i am not sure how that one is going to work with a diesel since it is vacuum powered.

5. the truck will be my everyday driver when finished. i help my brother run our family farm so it will be used for towing a couple times a month but nothing heavy duty like towing tractors or anything. just a 16' flat bed tandem trailer and a 17' tandem cattle trailer. i am planning on putting a tow bar underneath as well. but again i wont be doing much towing at all and the towing i do wont be heavy duty. the 14 bolt full float and the dana 60 front should handle it fine.

6. i am going to find or replace gearing to get a chevy 14bolt full float and a dana 60 front end to 3.73 gearing. so i shouldnt have any trouble with towing and i should pull around 20mpg on the highway. i dont want too low geared and be diggin for nickels in the couch just to go to town LOL.

hope that gives you enough to chew on your thoughts for a little while thanks for the questions. i always apprecate help.
Jonathan

thank you for your support to us!!!!!! it means a lot more than most people realize when american civilians and prior service members have the courage to outwardly show their support for the U.S. military. we can use every bit we can get. once again thank you very much and as soon as i start this project i will keep you updated on it and send what pics i have.
Jonathan

Thats pretty well thought out, Jonathan. I'm driving a Dodge 2500 Cummins, NV5600 6 speed, Dana front and rear 3.73:1. I'm planning on about the same set up in my 65 1 ton, as I mentioned above. Let me confirm your theory 'cause its about the same set up your talking about.

I am confronted by green people often that I should feel guilty driving such a monster. So I do the math in front of them. I easily get 20-21 mpg highway with up to 2 ton of trailer with the AC on. The Dodge gas models get 10-11 mpg in the same config. So until diesel is over twice the price of gas, I drive the monster. I have personally confirmed those numbers. In Diesel Power mag and on the 4bt.com web site, there are anabundance of stories of tweeking 4 and 6 cylinder cummins to 400+ HP and STILL get 20-22 mpg. Lastly, How many trips will it take to get 13,000 lbs of hay out of the hills in the mud in a chevy s-10 that gets 20-25 mpg? One in my PU.

So, yeah I like your planned set up.

well thank you. i appreciate your help and curiosity about my project. let me also add something to your argument with these "green" people. yes diesels expel alot of smoke so people see it and think its polluting more than gasoline motors but this is not the case at all. diesels produce mostly carbon dioxide which is filtered through trees. usually the green folks complain about the methane produced but that is also filtered by trees. and lets not get into ethanol and corn diesel. both of those products cause more pollutants to refine then normal diesel does to run in a vehicle. i could go on poking holes in global warming for hours. the ice caps are thicker than last year and getting bigger. the earth has natural warming and cooling cycles in 3, 5, 7, 10, 25, 50 and so on year increments. but my favorite one to use is this. when a volcano belches gas from inside the earth's core it produces more pollutants and hydrocarbons than the world's automotive industry does in ten years. so i dont think we are hurting anything much in the grand scheme. green folk make me giggle and this new methane scrubbing law makes me sick! anyway sorry to rant. thanks for the project advice its nice to know that someone else has a somewhat similar setup that they love.
Jonathan

Jonathan,
You've got a lot of work ahead of you!
Here are some more suggestions and replies to some of your answers/questions above.

2. I don't remember the brands, but Diesel Power magazine has talked about all of the different aftermarket Duramax wiring harnesses at some time or another, finding one that suits you needs is a critical part of this convrsion. You could also get some input and advice on that and your entire project at www.4BTSwaps.com.

4. I wouldn't use rear disc brakes unless you already have front disc brakes, or swap to disc front and back at the same time.
For the booster, ditch the vacuum booster and use a hydrobooster, they work off the PS pump pressure, are smaller, and much better/more powerful. Lost of info and advice can be found here, as well as parts if needed. http://hydratechbraking.com/hydroboost_faq_old/

6. Do you already have the axles you want, or will you be swapping some? Just curious, I don't have any advice here other than try to make the tires fit under the fenders if possible.

This calculator may be helpful for calculating what gears you need http://www.onlineconversion.com/bigger_tires.htm
Tire size makes a significant difference, so pick that, pick how fast you want to drive, know your OD ratio in the transmission, decide what RPM the engine gets good mileage (I'm not sure for the Duramax, but guessing 1,800 or so?), then calculate what axle ratio you need to get you there.

Sounds like fun,

Grigg

i will be swapping the old drum axles for newer disc brake axles. i am trying to find a set of D60 front and D70 rear or D60 front and GM 14bolt full float rear with 3.73 gearing for the the amount of towing i will be doing, which isnt alot but some, and the transmission and evrything the 3.73's seem the best option for good performance and decent mileage. and as far as the tires go i really want to put some kumho Mk71 33x12.5x18's under this truck on matte black ultrawheel magnus rims. i would love to have 8-lug axles but it isnt a must. i dont know if those size tires will fit though but i sure hope they will.
with the wiring harness for the motor i will have to get on the other forum site and get advice cause i dont really know anything about that. the mechanics i will be working with should know plenty but right now i wouldnt even know what to look for. i do know that i found a duramax and talked the seller into leaving the ECU on the motor so that is oneheadache out of the way at least. thanks for all the help.
Jonathan

I'm right there with you Jonathan. Look for 2500 HO and 3500 Dodge diesels for your suspension. Dana 60 front Dana 80 rear in 3.73:1. 93-? At least that is what mine has. They will fit with little mod.

Google the wiring harness. I've seen new harnesses to adapt to whatever, how-to on adapting the original harness to another application, and how-to CDs to build your own. E-bay may be of help to. Try this site's vendors. There is something out there. I can't imagine that you're the Lewis and Clark of Duramax wiring harnesses.

thats very true i am sure. so you know the d60 front and d80 rear axles in 3:73 are in 93 dodge 2500HO and 3500 models? what side drop are those? driver?

Let me regroup. My 2002 2500 HO came with that setup. The dealer told me that it was a special order and was intended for a snow plow setup and the buyer reniged or failed to get credit, so I got it. Dodge might have used other setups. I've been told that the HO Cummins could only been hat with a 6 speed tranny (NV5600). So some 2500's and the 3500 may have that setup. I'm sure you'll check each item out speciffically.

I'm not sure I understand "what side drop are those?driver"

Dave

ok sounds good and yes i will be looking for each part specifically if i can take the axles from one truck i will but if not no biggie. i have been researching the D60-D80 combo and it is looking like the desirable setup for me. both axles are very strong and have lots of aftermarket support. it looks like they come in the 3.54:1 ratio which i think will also work fine for what i want to do but if not i can always switch out the gearing.

what i meant by " which side drop does it have" is which side is the differential on. driver or passenger. which side would i need my T-case to drop to?

Also i believe i have aproblem with my build plan but i am not sure. i always wikipedia all the parts i want to use for their specs and such and i found that the 6.6L LB7 puts out 520 ft-lbs and the ZF S6-650 is rated to handle a max of 520 ft-lbs. to me this sounds like i need to find a different six speed transmission that is made for more torque. However, the manufacturer used the 6.6l duramax with ZF S6-650 configuration from 2001 to 2006 i guess there just must be something i am not understanding here.
thanks
Jonathan

If I remember right the trucks with manuals didn't have the HP and torque of the ones with the Allison, probably detuned by the computer to make the transmission survive, that's my guess.

I don't know if you have any other manual transmission options behind the Duramax, what else bolts up?
I'd also look in the medium duty trucks, I bet some of those had 3000 series Allison's which should have an SAE bellhousing, and if that is the case then with a flywheel that may not exist you could use a number of different medium duty 5 and 6 speed manual transmissions that should hold the full power and then some.

Grigg

ok so lets just say that that combo is not feesible for one reason or another. if i was to get an automatic allison tranny would i be able to mount the controls on the floor or do they have to be steering column? i need a floor mount for this truck.
Jonathan

The Allison is electronic, no shift linkage. Allison has a little shift box with buttons and a display that can be mounted on the dash or console. I'm not sure how you adapt that to the GM wiring harness, could be simple, could be difficult?
The short answer is there is probably a way to make it work without a column shift.

Grigg

I don't crawl under the Dodge too much, I'll try to remember to look at which side the T-case is on.

Check and see if the NV-5600 can be adapted to the Duramax. It handles the Cummins 5.9 HO. I have heard they are expensive to repair.

Dana 80 is not indistructible. When I took mine in 'cause of a rumble on engine braking, the diff was bone dry and the bearings fried. My mechanic got it apart and found a spider had built a home in the vent tube on top of the dif. We theorize that the dif built up heat and blew out the front seal and dumped the fluid while I was on the road. I don't have any on the driveway. Luckily, he was able to salvage the ring and pinion gear ($$$) but it still soaked me to the tune of $700.

Over on 4bt.com, I have heard mention of adapting the electronic shift mechanism for the Allison but didn't pay attention. I'll bet somebody has done it.

alright thanks alot guys. i will get started researching this new issue hardcore maybe i will have some kind of a solution before i am home and tearing things apart.
Jonathan

My dream is a 47-54 with a duramax & allison trans combo. If money were no object it would have happened by now. I think your truck will be the coolest thing around. Good luck and keep us posted on the progress. I hope your dream comes true.

thank you. i hope so too. if 12,000-15,000 dollars and two months of nothing but working on this truck cant get it driveable than i dont belong anywhere near a build. thanks for all the support guys. i know i will have more questions LOL. i never seem to run out. but i have learned a ton these last few months with you bolters. hope to become one soon myself. i'll keep you updated once i start. thanks.
Jonathan

How about putting your truck body on a newer frame W/ the drivetrain already installed.
Bob

i have other posts where i discussed this but i dont want to do that much sheet metal work. there are no trucks now that have the same wheelbase measurements i would have to make the cab an extended cab or cut the bed to make it a short bed. i want the body intact and am gointo do the parts swap. i have almost a years worth of posts from when i started thinking and talking about this build with all these knowledgeable guys on here. it has transformed a thousand times already and havent even put a wrench to it.

The front driveshaft will be the issue ,the 65 K20 front driveshaft hooks up on the passenger side the later TC is on the driver side.You could possibly buy an adapter to install a NP205 to the allison or the ZF.Try www.advanced adapters.com that's where I purchased mine to adapt a 4L80E to the NP205.I also used 73-87 front and rear differentials to gain the turning radius and durability.She's not all done but making progress.