[13jraven]

You mean something like this?

The picture is of a low mile LLY i pulled from a wrecked 2005 2500HD. The NV4500 is just there for reference so you can see the size of the motor.

But hemi43 is right, if you have to ask big man where to start, you probably shouldn't.

But since you inquired, you have two choices - either put a blazer body on the duramax frame or put the duramax in the blazer frame.

The first one seems to be the most popular swap as the frame already has the d-max motor set in it. Just need to shorten the frame to 104", set the body on, make cab mounts and figure out how to mount the clip with radiator, coolers and intercooler. Personally, I dont like to see the frame hanging down under the rockers as the frame of the d-max is tall. So guys will add big rock sliders or steps to try and cover it up. But you can still see it. And lets face it, while the stock IFS blows you do have the massive AAM 11.5" rear axle.

The second one is way cooler and more difficult - put the d-max in the blazer frame; this will require more work. You have to start with finding upgraded one ton axles. 35 spline dana 60s and 14 bolt at the minimum b/c I wouldn't run 900+ pound motor, 200+ pound allison with 360HP/660TQ on a D44/12 bolt. A tune and exhaust will take a stock duramax to 600HP/900TQ. A bi 14 bolt with 10.5" ring gear is small compared to the 11.5" AAM axle in the duramax. Then you will have to fully box the frame complete from end to end with new cross members and figure out a cool way to set the motor in there so you can shut the hood.

What are you going to do about trans? The Allison would be the way to go but I have seen both 4L80s and NV4500's used in swaps but those are on detuned motors. And what about a transfer case. You can go with the stock Duramax TC but that is driver side drop so you will need to find a Ford Dana 60. Or you can find a passenger drop NP205 to mate to a chevy trans and keep the passenger side drop axle. The Allison will take a decent amount of sheet metal work on the trans tunnel to get it fit as it is dramatically bigger than a stock trans.

A few people make standalone harnesses - PPE in Fullerton, CA does a nice job. There are others that can make the harness and load a few tunes - you will need a way to disable the VATS, emission and all the other BS that will keep your truck in limp mode. You can run stock gauges with the standalone harness.

Figure new suspension as the extra weight will require upgraded leaf springs or coilovers. If you go coilovers then you have to go 3 or 4 link. With a shortened frame you are going to have wheel hop, so figured a rear traction bars.

You will need to figure out fuel system, cooling and plumbing. That is where the real time and money will happen as I am not sure a stock intercooler, radiator, trans cooler, condenser will fit in the blazer.

Lastly, don't forget about 4 wheel disc brakes.

Few questions, you ever measured a duramax out of the truck? Height, width and length and compared to a gen 1 blazer? While it is comp to a BBC just with a lot more girth. I bought my LBZ new in 06 and have driven daily ever since. I like to think I am pretty familiar with them.

The duramax swap feels like the offspring of a LS and 6.5 diesel mated together.

Did I miss anything?

JR