Overdrive trans for small block 340

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

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.

Isn't that trans computer controlled? how do you get around that??
thanks for the response.

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.

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.

You need to control the OD and lock up functions, See the link they sell them also...
link

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

https://www.gearvendors.com/index.html

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.

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

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.