04 2500HD Diesel Swap

[496truck]

So, lets BS about this for a minute.

My nephew bought my old truck. It's an 04 2500HD with the 8.1 and Allison, if you need more details just ask. At the time he was really hard up for one with a Dmax but could not find one in his price range much less in the immaculate condition mine was in. He loves the truck but still feels like he's missing something by not having the diesel. He's young and in the Marines and has some friends with hopped up Dmaxs and I don't think he's done anything to the truck to keep up with them, maybe an exhaust and intake kit.

So, he calls me yesterday. "Hey, I found a Dmax up in ME complete engine, harness, computer, etc. for 'x' amount of dollars." Now, I don't know what else he would need to attempt a swap in that truck. Fuel lines, pumps, the tank, intercooler and pipes? And then there's always the little things that take a swap like that from simple to irrational.

After thinking about his idea a bit, my first thought is; Why not put that 'x' amount of dollars into the truck as is and get more out of it? I know the aftermarket support for the 8.1 isn't quite as big as the Dmax but that engine is no slouch either. Let's say 'x' amount is $2500. I would think he could go a long way to making the 8.1 as much of a tire fryer as a Dmax.

But I don't know diesels. What say the CK5ers?

 

[badriver19]

Ive been in the diesel swap scene for quite a while and after reading and researching for hours upon hours, I think i have only seen one or two duramax swaps into a non duramax frame of the same vintage. Aside from the cost of the drivetrain, there will definitely be a lot that goes into it but it can be done. It would just turn out much cleaner and reliable to sell the truck and buy a truck with a duramax. That is just my take on the swap.

Im not sure if you were trying to compare the 8.1 to the duramax or not but they just simply dont compare. My dad owns an 8.1 and they are, as you said, no slouch. I believe that stock vs. stock, the 8.1 would take the duramax. but the first cent of aftermarket money spent, and the duramax takes it hands down. It would take alot of work to get the 8.1 to do what the duramax can do with EFI live and a built tranny, let alone a larger turbo or even injectors down the road. The fuel efficiency will be night and day with the duramax in the high teens-low twenties on the highway vs. the 8.1's high single digits-low double digits in stock trim on the highway. The reliability and drivability modded will be better with the duramax I would assume as i have never driven a heavily modded 8.1. The 8.1 does pull a trailer really well from experience but it doesnt sound like that was any part of the goal here.

Maybe its worth it to him to do the swap. He would learn a lot from the experience but I would drive the 8.1 for a bit and save for a duramax. I actually will be buying a newer duramax or cummins towards the end of the year once we are settled into our new house.

 

[496truck]

Thanx for the info. But that leads to the deeper question, it's not just a bolt in and go kind of swap is it? If this was something he was serious about doing wouldn't he be better off buying a wrecked Dmax truck from salvage and swapping it over? Having everything you need in the donor truck right there?

Or is it easy enough to gather the big parts and it'll all just drop in?

My thoughts are that there are major differences between the 2 trucks. I'd hate to think he gets most of the way through the swap and then gets held up on some details or even major problems he didn't expect. And then he's making payments on a truck that is nothing more than a big paperweight.

 

[rjfguitar]

It's actually a VERY simple swap to go from an 8.1L to the Dmax, a lot of people have done it. Here's how:

Step 1,



































Go to a dealership that has a Dmax truck that you could see yourself owning and trade in your 8.1L truck for the Dmax truck.

Step 2, there actually isn't even a step 2, it's THAT simple.

 

[jekquistk5]

If hes already making payments trade it in.

 

[63chevyll]

I have read where guys are swapping the dmax into newer suburbans and everything has to be changed, dash, dash wiring, chassis wiring, engine harness, so Yup, a doner truck is needed

 

[6.2Blazer]

In this situation where the identical truck with a diesel engine was available from the factory I really don't see the logic in doing the swap. I can see if you had an 8.1 truck with a blown engine and picked up the D-max stuff cheap but can't see tearing apart a perfectly good 8.1 truck, especially if he's still making payments on it. The Suburban swaps make some sense since that option was never available from the factory.

You mention $2,500.........if he was able to pick up a complete D-max setup that sounds like a good deal based on my limited knowledge.

 

[496truck]

If hes already making payments trade it in.

At the time, it was his first major purchase. Limited credit or even no credit. He was financed 10k and has been paying me the difference as he saves (almost paid off too, on my end). The payments on the loan part had been on auto pay from his account so his credit should be good, was even able to refinance the loan to a better int rate. His credit may be good by now to finance a newer truck if he wanted.

But that adds expense in itself. Higher insurance, taxes, etc... All things to consider when you are 20 and living off of service pay.

So, is the consensus pretty much, find a truck that is already equipped with a Dmax and buy that?

 

[Smokinthehippies]

yeah,

do not dick with the swap. he'll end up with way more headache not to mention a truck tha doesnt move for X amount of time.

if he's dead set then he should work on selling his truck to get closer towards a dmax truck.

i def wouldnt spend any money to pep up the 8.1, all he's gonna do is get more in debt and still get spanked by a stock dmax with just efi live. plus getting 1/3 the fuel mileage.

 

[rjfguitar]

But that adds expense in itself. Higher insurance, taxes, etc... All things to consider when you are 20 and living off of service pay.

So, is the consensus pretty much, find a truck that is already equipped with a Dmax and buy that?

How about resale to figure into the equation. As soon as the carfax is ran, everyone will know it was a gas truck, and obviously that would make a LOT of people nervous about the truck, after all, a buyer could just find another truck that came factory with the Dmax. I mean, would you want to buy it? Sure, if it was a Burb, and you really wanted a diesel burb, your choices are limited, but when there is a Dmax HD on every lot from CA to NY.....

 

[ktmoutfront]

Maybe he should just save a whole lot of money and get friends driving the 6.0 trucks. That's the cheapest way to go. I had a 8.1. Towed small ok. Put 15k behind it, and the D max puts it to shame.

 

[496truck]

After some more thinking, he decided against it.

Like I said, it used to be my truck. It towed anything and everything I needed it to tow. But, being in my 30s, I never saw it as a race truck or performance vehicle.