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Overdrive trans for small block 340 #3094171
11/14/22 03:33 PM
11/14/22 03:33 PM
Joined: Apr 2005
Posts: 1,505
TN
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SCATPACK 1 Offline OP
pro stock
SCATPACK 1  Offline OP
pro stock
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Joined: Apr 2005
Posts: 1,505
TN
Does anyone offer or has anyone installed an overdrive automatic from a later model truck/Dakota 5 speed into a Duster or Demon
Have a 340 Demon that really would benefit from an overdrive trans
Any help appreciated
Any pictures or details of what work and modifications are required would definitely be appreciated
Thanks
Jerry


Old Geezer Racing
Re: Overdrive trans for small block 340 [Re: SCATPACK 1] #3094186
11/14/22 04:36 PM
11/14/22 04:36 PM
Joined: Mar 2011
Posts: 3,056
Michigan
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A727Tflite Offline
master
A727Tflite  Offline
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Joined: Mar 2011
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Michigan
Find yourself an A-500 - 42/44RH.

Will have the low gearset in it, bolts right up to your block.

I can’t speak on what alterations are needed to install but I’m sure someone here will tell you.

Re: Overdrive trans for small block 340 [Re: A727Tflite] #3094251
11/14/22 10:59 PM
11/14/22 10:59 PM
Joined: Apr 2005
Posts: 1,505
TN
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SCATPACK 1 Offline OP
pro stock
SCATPACK 1  Offline OP
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Joined: Apr 2005
Posts: 1,505
TN
Isn't that trans computer controlled? how do you get around that??
thanks for the response.


Old Geezer Racing
Re: Overdrive trans for small block 340 [Re: SCATPACK 1] #3094258
11/14/22 11:51 PM
11/14/22 11:51 PM
Joined: Nov 2006
Posts: 2,252
IL
furious70 Offline
top fuel
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IL
I have an a500 behind my turbo 383. You don't need to worry about the power or the BB bell on it, it would work well. It's operated with 2 pressure switches and a hobbs switch to downshift on WOT.


70 Sport Fury
68 Charger
69 Coronet
72 RR
Re: Overdrive trans for small block 340 [Re: SCATPACK 1] #3094261
11/15/22 12:08 AM
11/15/22 12:08 AM
Joined: Mar 2011
Posts: 3,056
Michigan
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A727Tflite Offline
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A727Tflite  Offline
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Joined: Mar 2011
Posts: 3,056
Michigan
Originally Posted by SCATPACK 1
Isn't that trans computer controlled? how do you get around that??
thanks for the response.


The RE series MUST have the PCM to function properly, the RH needs either the PCM or a series of switches and and sensors to achieve 4th gear. 1,2 and 3 are fully automatic like a 904/727.

Of course manual shift valve bodies can eliminate the need for much of the electronics.

Re: Overdrive trans for small block 340 [Re: A727Tflite] #3094281
11/15/22 07:47 AM
11/15/22 07:47 AM
Joined: Jan 2021
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rust belt
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Moparite Offline
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rust belt
You need to control the OD and lock up functions, See the link they sell them also...
link

Re: Overdrive trans for small block 340 [Re: Moparite] #3094306
11/15/22 10:33 AM
11/15/22 10:33 AM
Joined: May 2005
Posts: 4,679
Florida
BDW Online content
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BDW  Online Content
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Posts: 4,679
Florida
Check out this link, everything you need to know for 500/518.
If you go this route, get the 518, it's like having a 4.5 spd.

http://www.cuda-challenger.com/cc/index.php?topic=84774.0

Re: Overdrive trans for small block 340 [Re: BDW] #3094331
11/15/22 12:11 PM
11/15/22 12:11 PM
Joined: Oct 2003
Posts: 7,135
my own world
theraif Offline
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theraif  Offline
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shruggyhttps://www.gearvendors.com/index.html

Re: Overdrive trans for small block 340 [Re: BDW] #3094335
11/15/22 12:26 PM
11/15/22 12:26 PM
Joined: Mar 2011
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Michigan
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A727Tflite Offline
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A727Tflite  Offline
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Joined: Mar 2011
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Michigan
Originally Posted by BDW
Check out this link, everything you need to know for 500/518.
If you go this route, get the 518, it's like having a 4.5 spd.

http://www.cuda-challenger.com/cc/index.php?topic=84774.0


If you want a low first gear you can only get it standard in a 42/44. The 518/618 has 2.45 low like the 727.
Plus the lighter internals are worth some e.t. especially behind a small block.

Re: Overdrive trans for small block 340 [Re: theraif] #3094367
11/15/22 01:33 PM
11/15/22 01:33 PM
Joined: Oct 2007
Posts: 4,205
New York
polyspheric Offline
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polyspheric  Offline
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New York
W/r/t GV
Yes, but:
$$$$
OD is only 77.8%
Has less effect on engine speed than any of the factory transmissions but can be used in any gear. This has the effect of “splitting the gears”, viz. creating an intermediate ratio between each pair of the original gear ratios.
It allows double overdrive with an OD box.

I wrote an .xls that shows various ratio combination, RPM loss, MPH in gear, etc., PM for a free copy


Boffin Emeritus
Re: Overdrive trans for small block 340 [Re: polyspheric] #3094422
11/15/22 04:39 PM
11/15/22 04:39 PM
Joined: Dec 2009
Posts: 20,600
in a cattle trailer down by th...
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Guitar Jones Offline
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Guitar Jones  Offline
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in a cattle trailer down by th...
I ran across a face book group for swapping the 8HP transmissions to LA and Magnum small blocks. I can't find it now, but there are stand alone controllers now with the popularity of gen 3 hemi swaps.


"Follow me the wise man said, but he walked behind"


'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion.
'74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost coming soon!
2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
Re: Overdrive trans for small block 340 [Re: Guitar Jones] #3095452
11/19/22 10:58 AM
11/19/22 10:58 AM
Joined: Jan 2003
Posts: 554
Mesa , Az
Jambbii Offline
mopar
Jambbii  Offline
mopar

Joined: Jan 2003
Posts: 554
Mesa , Az
Originally Posted by Guitar Jones
I ran across a face book group for swapping the 8HP transmissions to LA and Magnum small blocks. I can't find it now, but there are stand alone controllers now with the popularity of gen 3 hemi swaps.


Here you go!


https://www.soundgermanautomotive.com/

I'll be using them for my 8hp70 swap in the wife's durango.


I'm also using 47RE in my challenger. Going to have a manual VB and a switch for OD. Pretty basic stuff.


70 Challenger
1960 Town Wagon P Pump 24v cummins project
06 Mega 3500 Drw 2wd
12 Durango R/T
18 Power Wagon
67 A100






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