6.6 Duramax in 1500

honda65 · January 19, 2022

Hi,

Does anyone know if a 6.6 Duramax would fit in a 1500? I have a 2021 3.0 Duramax which actually runs pretty darn good and gets excellent fuel mileage. But I had a 2020 2500HD last year and of course I miss that power.

I'm sure it wouldn't be cost effective by any stretch but I was just curious if anyone knows if it could be done. How much different are the dimensions between the 6.6 and the 6.2?

HeySkippyDog · January 19, 2022

Uhhh, really? Is this a real post?!

A 6.6 Duramax of the vintage you speak of is extremely overpowered for a 1500.

Will it drive? If you can shove it all under the hood, but good luck getting that to work.

A 1500 is not a HD.

Transient · January 19, 2022

I have a 6.2 in my truck. Not much space to work with. And, from what I understand diesel engines are heavier. That might meaning beefing up the front suspension to handle to weight. What you add in weight you'll lose in payload and towing. Imo, if GM wanted to make a 1500 HD they'd do it. They've done it before. I did the trans fluid and filter on it. Getting to all the bolts was a PITA at one part of the pan.

Edited January 19, 2022 by Transient

TNTSierra · January 19, 2022

I couldn’t even imagine how many pre owned HDs you could buy with this attempted swap!

you could always just drop in the big block Chevy with 1000 HP for $30k

AirForceAngler · January 19, 2022

With the right fabrication skills, just about anything can be done. It would be neat, but require a lot of work and customization. You'd also need some front suspension upgrades as the Duramax and Allison is quite a bit heavier than the gas motors.

newdude · January 19, 2022

Uh...no. Trade it for a big one?

shakenfake · January 19, 2022

Guys used to do diesel swaps in the GMT-800s and 900s 1500 trucks all the time. Nowadays probably no since it is harder. Would be badass though

f8l vnm · January 19, 2022

But why not just get a HD ? So you can also have the thick frame/suspension/etc

Silverado4x4 · January 19, 2022

Front suspension will not hold the weight and the Allison tranny is bigger probably won't fit in the transmission tunnel rear diff won't handle the power and torque.

FiatDale · January 20, 2022

Theres a reason the 2500 / 3500 frames are taller - so the motor / Allison can fit. All previous gen 1500 diesel swaps typically had a body lift in them for the extra space. But aside from height, the engine bay is the same size from 1500 thru 2500.

And yes - much beefier suspension. Frame would hold it with some mount modifications.

Edited January 20, 2022 by FiatDale
Added frame and suspension info