Technical 440 Overdrive

I have an early 70s mopar 440 I'm going to be putting in a 55 DeSoto. Would like to have overdrive for cruising and towing. Does anybody know of a heavy duty later model overdrive that will bolt to the 440?

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Gear Vendors has a unit that will bolt to the TorqueFlite. Haven't owned one, but have heard great things about them.

 

No automatics that I'm aware of. Above is as close as you'll get. Or you can adapt a 700R to it, which will probably be a bit cheaper but not as HD...

 

I had an acquaintance who put an early hemi in a 55 DeSoto, he used a 727 ? Auto with the Gear Vendors unit. They aren't cheap, but they work very well. I had one in an OT vehicle (it was 35 ft long and slept 6, so really OT) and it worked great for thousands of miles behind a big block. A lot of them went behind the big blocks and Turbo 475 ? before the HD o/d transmissions came out.

 

Get a 46rh trans out of a 90s pickup. Trans will have a small block bell. Cut off the bell and buy an ultrabell for a bb.

 

In terms of automatics, there is no cheap route. Notice I didn't say no easy route. You have options that are readily available. They're just not inexpensive. The main issue is that even garden variety big Mopars put out a load of torque that can destroy weak driveline components not up to the task. So much of the cost is related to the need for heavy duty components rather than inexpensive, light duty stuff.

The Gear Vendor's unit is a viable option, but it's a long set up and may require major floor clearancing, doesn't have a particularly steep OD gear at .78:1, is $3,100, and must be manually engaged by switch.

The path I'd personally go with is an adapter plate to a 4L80E, which will require a computer to run. The TCI EZ-TCU seems to get some great reviews, and seems easy to install. It's basically a TH400 with OD, at .7:1. You can get the adapter from Wilcap and various other suppliers.

 

Not gonna be cheap.
https://transmissioncenter.net/shop...ge-small-block-518-transmission-6-bolt-crank/

 

The trans center adapter is what you want.
You will recall that internally, a small block trans is essentially the same as a big block. Also, there are plenty of HD parts for any TF trans. Now, the problem area is in the OD unit itself and if treated harshly it may die a quick death.
The A518 should be adequate for any daily driver.
The bigger question is whether or not you have adequate space to put the thing...

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Id get an A500 and an Ultrabell. The A500 is non electronic and you can use a switch to control the overdrive.

 

run an 8.75" rear, there are a lot of gear ratios available. You didn't mention how much weight you'll be towing, but it's likely that it won't be heavy enough that you'd need to have steep rear gearing. As mentioned, the 440 does make some torque, so use it to advantage. I'm guessing 2.93 or 3.23 will work well, with a 727, no overdrive.

 

A 440 is an easy engine to gear. We used to consider a 3.26 gear to be a deep gear in a car like a Road Runner or a Cuda. There is no real reason to look for an OD. Gear it like you want to drive it. A 2.89-3.08 gear will get you down the road well enough and a 3.2-3.3,5 gear will win stoplight to stop light.

Now if that was n too deep for ya, a 3.26 gear will also do fine on the highway unless you want to drive 100+ MPH.

I know that I am not finding an OD for ya but I am telling you what I would do and I have been getting by for a long time.

 

The A500 is the old 904 version with OD, I would not use that one behind a big block.

The A518 version is a 727 with OD. The earlier ones were hydraulic controlled, not electronic other than TCC and OD apply which could work without computer control.
This would be the better choice.
You would still need to do the Ultra Bell as there were no big block cases as far as I know.

Bill