Author Topic: 12v swap  (Read 1374 times)

Offline 2011laramie

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12v swap
« on: April 23, 2017, 09:56:26 AM »
Would it be easier to do a driverside drop t case and matching axle to do a 12v swap in a crewcab 3500?

The parts truck im looking at doesnt have the original d60 up front anyways, its been robbed.
« Last Edit: April 23, 2017, 10:00:40 AM by 2011laramie »

Offline Irish_Alley

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Re: 12v swap
« Reply #1 on: April 23, 2017, 10:33:42 AM »
depends on your trans. you NEED OD
Chevy trans options 4l80e or nv4500 (cant build a 700r4 to handle the tq)

if you go with gm trans you have to find an adapter plate and flywheel for gm.
then decide what transfer case you want to use. a 208 would be cheaper and more practical. if you have to use a 205 then you need a round pattern, you can have either the short or long input shaft. with the long shaft you will need a spacer (about $100)

If you go with the 4l80e you also need a standalone computer, convert to manual shift and you need the right adapter for the transfer case. also with a standalone you will need a speed sensor, you have two options on this. either on the tail shaft of the transfer case (88+) or one for the rear axle


a dodge cummins 4x4 donor would be your best and cheapest option, but make sure you get a trans with od. the early dodges had no OD
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Offline 2011laramie

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Re: 12v swap
« Reply #2 on: April 23, 2017, 11:11:35 AM »
I was thinking dodge everything. 12v, tranny, tcase and a front axle. Definitely need OD.

Offline Irish_Alley

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Re: 12v swap
« Reply #3 on: April 23, 2017, 11:58:16 AM »
also the dodge v10 and cummins transmissions have the same bolt pattern different than the gas tranmissions
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline 2011laramie

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Re: 12v swap
« Reply #4 on: May 13, 2017, 03:00:38 PM »
So this is what i have so far.
Truck is a 78 crew cab with a 350 and a sm465 and 10 spline 205.
Ive got a figure 8 32 spline 205
An original 4l80e with matched 205 with vss from a 1991 1 ton crew cab that had a 454. Was told it drove

The cummins im geting is a 1990 non intercooled with a" built" 727 3 speed and a passenger side drop 23 spline 205.

I want an auto... wait, ive been told by my better half the truck has to be an automatic.
 I see advance adapters has kits for 10spline and 23 spline to be converted to 29 spline.

So im open to all ideas.

Build up the 4l80e i already have. Would need a computer, bellhousing adapter. Torque converter
Try and get a 47rh or 47re or 48re. I believe these are all 23 spline output shafts. Also would need a computer
Or a allison with the 29 spline adapter (really not likely to happen)
Im planning on a mild like 260hp maybe 570ft lb torque goal for the cummins. So nothing extreme. But more than a stock tranny can hold

I plan on running 35" tires. So with 4.10 gears and no OD id expect 2650 rpm. Instead of switching to an od tranny i could look into swapping to a 3.42 gear ratio which would bring it down to 2250rpm.
« Last Edit: May 13, 2017, 03:47:42 PM by 2011laramie »

Offline Irish_Alley

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Re: 12v swap
« Reply #5 on: May 13, 2017, 04:34:28 PM »
ok so your setup is going to be similar to mine, except the power. i have a few TCUs one from TCI one from GM. they need a few signals to work with the 4l80e. since you have the trans already i would stick with the gm stuff. your adapter is going to be the deciding cost factor, you can get a new one or try to find one for the bread van's 4bt. yes they bolted to a th400 but its almost the same trans 4l80e, so everything will swap over.

if you dont want to tilt your engine you have to get a new adapter and flex plate which will cost you more. either way you have to think about your engine mounts and how much thats going to cost. if you get the bread van adapter you can drop the cummins in move the trans back 3" and cut the firewall. baja sells his mounts and you dont need to push the trans back or cut the firewall and it uses dodge/cummins motor mounts. but im sure you cant have the motor tilted so you have to have an aftermarket adapter
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Offline 2011laramie

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Re: 12v swap
« Reply #6 on: May 13, 2017, 10:20:28 PM »
Irish what are you running for a torque converter and did you build up the 4l80e at all?

Offline Irish_Alley

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Re: 12v swap
« Reply #7 on: May 14, 2017, 02:47:04 AM »
im running the stock setup. the torque converter isnt holding up too well. its still locking but im not sure if its cause i didnt know what i was doing when i locked the converter while driving but here lately if i lock it you can feel it but not like it used to
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Online bd

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Re: 12v swap
« Reply #8 on: May 14, 2017, 04:36:37 PM »
Irish, check the fluid pressures then look into a Hughes Performance XFM model torque converter.
Rich
It's difficult to know just how much you don't know, until you know it....
In other words... if people learn by making mistakes, by now I should know just about everything!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)