1998 2 Door Tahoe Dmax/Alli Conversion.

[racerx573]

Hey everyone, new guy to the forums here, but long time site reader..
I have been looking into putting the Duramax/Allison set up in my '98 2 Door Tahoe.. I figured it would be something radically different, and would turn some heads. I have read every article I could find about the '89 C/K conversion. I do intend on buying the book about the conversion as well. I just had a few other questions regarding some things I could not find in the articles, and am not sure if it is covered in the book.

1. Do I need to use the front differential set up from the HD truck in order to keep my 4x4 (what set up was used on the '89 C/K?)?

2. My vehicle has AutoTrac push button 4WD. Will this work with the Duramax/Allison set up (i.e. if I need to use the HD's set up)? Or will I need to switch it to a manual set up.

I am looking to build a daily driver that can handle some decent off-roading (6" lift + 35" tires), something with under 500 HP (don't want to have to upgrade the tranny like the '89 needed done).

Can I pull off off at least just the engine/trans the conversion for $10 grand or so? I have been seeing used engines/trans go for $4-7K.
Any tips comments, etc will be appreciated.


Another option I was considering was, selling my Tahoe and buying a '72 K5 Blazer and doing a frame up on it, and installing the Dmax/Alli set up... thought that would be pretty sick too..

I love 2 door SUV's, especially the convertible ones, as well as the Duramax engine.. so I thought I could make the best of both worlds.

[More Power]

Welcome to the board!

To answer your questions....

1- I'm using the original front differential & suspension that came with the truck. I only use 4WD when launching straight at the track, so it's been able to handle the power so far (when I do my part). :D

2- Autotrac could be a problem. You could either use the pushbutton shift NVG-263 transfer case that is used in the newer HD trucks (like I am using) or install a manually shifted NP-241.

3- You could maintain the 4L80-E if you use the van programming to keep power within the tq limits of the transmission. 500 will overpower a stock Allison as well.... :) A beefier rear diff could also become necessary.

4- Though not essential, a 1" body lift will allow more hood clearance for an LB7. The LLY and LBZ require more hood clearance than an LB7. Of course, your proposed 6" lift will solve that problem.

5- You could do a conversion for perhaps less than 10K if you begin with a complete salvage truck to use for parts. Otherwise, the many required bits & pieces will run the cost up.

Good luck,

Jim

[racerx573]

Thanks for all the info. I am bidding on a salvage truck on ebay right now.. hopefully I can snag that and have my project begin this winter.
I will keep updates with what I do with my project.