Ok it’s been over five years since I retired and moved from Nevada to 175 acres in Usaho and all I have done is work and build build build. Although I’m still building the main home I found a project I am keeping.

Three years ago I found a running 92 Dakota club cab 318 magnum / auto .

Recently I bought a few Didfecsweotlines and had to buy a Rambler and gmc truck with the group. Today I traded the Rambler for a 39 Plymouth couple that I will grab next week

My plan is to use the Dakota chassis and at least the 318 Magnumbecause it’s strong and surprisingly fast says the guy used to a 450-6 Cuda. Not that fast but I was kinda surprised

I’m trying to decide on a trans and I own an 8 3/4 as I don’t even kniwcwhatvunder the Dakota.
It’s going to be a driver and no show car and I would like to use the A.C

I don’t mind an auto trans but would like it more like a slapstick and maybe more gears

Looking for suggestions and ideas !

It comes with an extra front clip and numerous fenders Ect. Needs floors replaced. Has debts and dings

Thx

Any idea if a 38 Plymouth front end will fit on this 39? I have a front clip minus the hood and I linda like the 38 much better ?

39 was a major redesign body and chassis wise.

t my 2 cents worth.

First thing I would do is identify the transmission that’s in the Dakota. I’m thinking it’s probably a 500 (904 based overdrive) or 518/46RH (727 Based Overdrive).

I’m not real well versed on the 500s but I am using a 46RH in my 37 Dodge truck. The primary difference between 518 and 46RH is that the 46 RH uses a lockup converter. There are various options for controlling the lockup and overdrive on the 518/46RH. In my case I’m using Compushift to control shift points, lock up and OD but there are simpler/cheaper options. The Compushift is a little pricy but once I got it dialed in a really happy with it.

Hemi 46RH by M Patterson, on Flickr

On the 518/46RH the front of the transmission is basically a 727. The valve body has the same shift pattern as the 3 speed 727 (PND21) with the OD being hydraulically controlled. It’s kind of a plus as any of the aftermarket 727 shifters will work with it (or if you’re so inclined a factory slap stick).

If you go this route I would recommend either 4.10s or 4.56s for gears. With the .69 OD ratio that puts your final ratio in the 3.15 range with 4.56s and 2.83 with 4.10s. I’m using 4.56s with 28” tall tires on my 37 and it comfortably cruises at 75-80 MPH ( at about 2800 RPM…..4.10s would drop it to 2500). It’s also a riot to drive around town in.

Not as exotic as some of the 6 and 8 speed autos but not as complicated or expensive either.

The Plymouth business coupe used the same body shell from 37 through 39, so the front sheet metal should bolt on, when used as a complete unit, there is probably a difference on how the fenders attach to the running boards. The individual parts like fenders, grill, hood, and hood sides are all different between each year, 37, 38, and 39. The 39 did use a more modern chassis with the independent front suspension, but you will get rid of that when you transplant the Dakota chassis.

I suggest you use the Dakota front clip rather then the entire frame, The Dakota frame kicks up pretty high in front of the gas tank and never comes back down. If you use the Dakota rear frame, you will end up raising the entire floor from behind the seat to the rear of the body about 6". But if you need floors anyway...with care, the steel box floor from the Dakota makes a pretty good rear floor pan for the coupe body. I did that with my 48 Plymouth coupe, and I have a few pictures.
The 39 frame and the Dakota frame join nicely at about the firewall.

As far as the 92 Dakota drive train, I would bet the trans is the 500 base OD, and the rear axle is an 8 3/8 (formally called an 8 1/4), it likely has 3:55 gears, and there is a good chance it has limited slip, but it also has 6 bolt wheels. The front hubs are also 6 bolt, but those can be converted to 5 bolt by buying new 5 bolt rotors. Everything else still works. As far as the trans, it won't care what you use to shift it, if you have an old slap stick, throw it in there.

AC, The Dakota heater/ac box is too wide for the coupe, however, the right end has about 6" of recirculating air duct work that can be modified. I was able to use the modified Dakota heat/ac unit in my 48, but I think the 48 is wider then the 39, you will have to measure. Using the Dakota heat box, I could connect the AC if I wanted to. There are some really nice compact heat/ac street rod units out there, but they ain't cheap, check Vintage Air. Most of the aftermarket heat/ac units are well designed, sort of a follow the directions and plug and play, there is little engineering required. Using the Dakota heat/ac will require some engineering.

My 48 Plymouth business coupe was a quick build. I parked the Dakota side by side with the 48 Plymouth, front wheels to front wheels. I made note of what had to move to line everything up from the front wheels. I noted where the firewalls were, where the motor had to set, how much the Dakota frame needed to be shortened, and where the rear end had to be. Then I removed the Dakota sheetmetal, and relocated what ever had to move to the proper location. I used nearly everything off of the Dakota, including the passenger floor pan, the firewall, the wiring & computer, the dash, the heater box, the steering column, and the box floor. I used most of the extra sheet metal as patch panel material.

Once everything was in its proper location on the Dakota modified chassis, I braced the coupe body, and cut the remaining floor out of it. I lifted the body, and trimmed the width of the Dakota until I could set the coupe body on the chassis. Then I went about connecting the Dakota floor pans to the coupe body shell. Remember all that extra Dakota sheet metal? The whole project took about a year to make it drive able (but not pretty), between working on other peoples stuff (to make a living).
At this point, this is the car's 6th summer on the road and we are just past 48,000 miles. Its a great driver. Gene

Just a quick note, most V8 Dakotas are going to have a 518/46RH behind them. The V6 Dakota most likely to have a 500/42RH.

There is no difference between a 518 and a 46RH, it was just a change in how the transmissions were designated. Both could be had with or without lockup depending on the application.

Cool project by the way. Good luck with it.

Yes, my 1992 Dakota shop manual states that the 42RH is used with the 3.9L and the 46RH is used with the 5.2L. The difference in the transmissions is the first and seconed gear ratios.



I know it's just me, but why would mother Mopar make things more complicated by having two designations for the same part!

Pertaining to the above posts, for those that don't know, (that would be nobody) the Dakota 6 stud rear axle can be retrofitted with the earlier 5 bolt
axle.

RUMBLON: Why would you not use the original '92 overdrive transmission ?

the 500 and the 518 are NOT the same part. Nor is the only difference the first and second gear ratio.

The 500 is essentially an A904 with an OD in the tail shaft.

The 518 is essentially an A727 with an OD in the tail shaft.

they retain all the differences between a 727 and a 904 as the 3 speed versions do.

That is not what I said, ...I was talking about Guitar Jones quote about the two different model designations for the same transmission, 518 and 46RH !

That is exactly what you said.

Around 1993 Chrysler decided to change the transmission designations to something that described them better. So a 518 became a 46RH. It breaks down like this.

4 = number of forward speeds

6 = an arbitrary number for its torque capacity. A 2 is less than a 6 and 6 is less than a 7 and so on. It does not correlate to an actual number, it's just relative.

R = rear wheel drive and

H = hydraulically controlled shifting.

A 904 became a 32RH a 727 became a 36RH a 500 became a 42RH.

When they went to electronic control the H was replaced with the E so an electronically controlled 4 speed rear wheel drive transmission became a 46RE, 47RE and so on. I'm not sure if there even was a 42RE but I don't know why there wouldn't be as they used the same valve body and overdrive unit as the 46's.

I did not say it was the ONLY difference. So I guess in hindsight I should have said ONE of the differences from a driving usage and street rod retrofit perspective, rather then a strictly technical point of view, that might or might not be important for the original poster.

So you are right,......I will not be posting on this subject again and will be very hesitant to post or participate on other then my build thread in the future.

I have no issue using the original trans if I can make it work like a slapstick or floor shifter of some sort. !

I picked this up and it’s gojng to need a few parts if I can find them

I could really use a trunk lid and idea if it’s a one year piece or not of if a didfecone would work. This one is hammered.

A set of rear fenders would make it easier but I can make them work.

Just wonder what others years parts fit the body ?

according to my hollander, 37-39 chrysler, dodge, desoto, and plymouth business coupe trunk lids interchange.
as for the rear fenders, 39 has different trim, but 37-38 chrysler, dodge, desoto, and plymouth will bolt on and work. the tail light holes may, or may not be the same.

Thank you very much. Whats a hollander? Book im guessing. Can i see a pic i will order one if available?

Thx again

the "hollander" is the bible of junkyards. it tells the interchange of almost every single part on a vehicle. it comes out every year, and is expensive. the one i quoted was the 16th edition. the copyright is 1949-50, so it covers quite a spread of years. it is a re-print i got many years ago, and i been meaning to get several other years, but i haven't got around to it. they are on feebag, and i think you can still get new ones from the original publisher in wayzetta, minisota.
the ones used today are on cd, as the yards have all gone digital.

A lot of 318 Dakotas had the 500 behind them. The 500 had the 2.74 low gear set and lock-up converter from the start. They are also more slender and will fit in a streetrod with less surgery.

Sorry for the double post,