8.1 to dmax 3500 HD GMT-400 body

malibu795

malibu795

misspeelleerr
Apr 28, 2007
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how different are the wireing? i read alaska AV dmax swap into his avalanche...would it be almost plug n play same ECM/TCM?? IMO everything else is easy..
weight wise as a hotshot setup running 26,000GCVW i can put 13,200 on the truck... with 5% cushion thats ~12,600lb payload. 350-400hp is the target range with that said minimal weight increase is ideal... built 4L85 or ZF6/NV4500 IMO would serve better then the 350-400lb allison
i can get these with a 8.1/allison which IMO would make for a better canidit for a dmax swap vs 6.5/4L80 would. 200hp even with 4.63 gears makes me little faster then fully loaded semi...
485203_3286774121767_1040072946_3098270_296148031_n.jpg
 
malibu795

malibu795

misspeelleerr
Apr 28, 2007
7,854
284
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yep 01 and 02 models had two opitons 6.5td/4L85 or a 8.1/allison
never made an 03 then 4500 kodiak took over
15,000 gvw and the 159"wb wieghs 6400lb as a chassis cab. 98 and newer are doubled framed 3/8" for both.
 
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RKTMech

RKTMech

Idiot with a wrench
Aug 18, 2008
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The Norco's
That things awesome, LLY and before would be the easiest, but any thing is do-able, I.E. time and money! Great swap idea, :thumb:
 
THEFERMANATOR

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
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A 4L80E behind a DURAMAX with any weight would live a very short life at derated stock output(theres a reason teh vans with them only got 250HP and 480 torque). The extra 200 pounds for an ALLISON over a 4L80E is a negligeable differrence for the reliability you would get from it too. As far as wiring goes, and early LB7 uses a very simliar wring code to the GMT-400 trucks. When I did mine most of the wiring colors all matched up. I don't know how this one turned out as he hasn't updated it recently, but he does have some pics of the engine in it.

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=35635
 
RKTMech

RKTMech

Idiot with a wrench
Aug 18, 2008
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The Norco's
Well the only wiring you'll have to look at will be the (iirc) the C-2 connection at the fuse box, and not that many wires. My 05 LLY into 04 LB7 was all plug and play. You will be getting engine, trans, and harness for your swap, correct?
 
malibu795

malibu795

misspeelleerr
Apr 28, 2007
7,854
284
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you got a link to where i can get that conversion CD at? i am not familure enough to figure out how to look up `pussow`

the catch with the tranny.. IDK if you know or not but on these truck then praking brake is driveshaft mounted on the tailshaft.
IDK if the allison trucks are tailshaft mounted or even they are still running D80s or AAM1150 havent had a chance to crawl around one.


BTW the 2886 and dmax fan blade.. 205* ect sustained is the max i get..thats 26,000lb up a 5% at 30mph(2nd gear) for 6 miles or high wind resistant loads... wouldnt do run it on a regular CK truck though.
thought you would like some feed back :beer

i know you pushed lotsofsmiles 4l85 failures in the thread you posted.
im going to ask him what actually failed.
 
malibu795

malibu795

misspeelleerr
Apr 28, 2007
7,854
284
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in the buckeye state
RKTMech said:
Well the only wiring you'll have to look at will be the (iirc) the C-2 connection at the fuse box, and not that many wires. My 05 LLY into 04 LB7 was all plug and play. You will be getting engine, trans, and harness for your swap, correct?
Click to expand...

thats one of two options.. currently the truck is my bread and butter went 1099 employee on 3/28/12 as a owner operator as a LTL flat bed/hotshot.

most likely buy another 3500 HD and do the work to that one while im out makeing money with this one.. need to find an 8.1 variant and look at the harness to see how close it matches my 02 lb7 if very similar buy that and do a repower.
option 2
find another clean 6.5(manual prefered) run stand alone/hybrid type setup

common sense would lead one to believe that the 8.1 even though in the GMT-400 body has then GMT-800 wiring..... due to the crossover years.....maybe???

i have a complete truck harness/ecm/tcm wise i can take stuff off of.. not that i really want tooooo.

ideally just be an engine swap. even at stock tune im miles ahead in reliability and efficency and maintance wise over the 6.5
 
z79outlaw

z79outlaw

New member
Apr 20, 2007
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Salem WI
malibu795 said:
thats along the lines my thought process was going..
the biggest thing is i need all gauges to work properly.. DOT would through fits if they DOT/inspected the truck and guages were not working...
Click to expand...

Gauges are easy original truck senders in dmax engine.
 
duratothemax

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
malibu795 said:
yep 01 and 02 models had two opitons 6.5td/4L85 or a 8.1/allison
never made an 03 then 4500 kodiak took over
15,000 gvw and the 159"wb wieghs 6400lb as a chassis cab. 98 and newer are doubled framed 3/8" for both.
Click to expand...

adam im pretty sure you're wrong about the allison.

the old gmt-400 3500HD's could be had with the 8.1 in 2001-2002, but they still kept the 4L80. Allison was GMT-800 only, ill put money on it.
 
JoshH

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
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Texas!!!
FWIW, the built 4L85E in my race van project is holding up well so far, but so far I only have 7 1/4 mile passes at the track and some street testing on it. It is a lot lighter than a fully loaded truck, but I'm also putting out a lot more power than what you're looking for (enough to trap at almost 113 MPH). If you want to talk to someone about its ability to hold up, Jake's Performance built mine. They could tell you whether or not it would hold up.
 
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