Drive Train Recommendations

[rockable]

I have now officially ruled out putting a baby Hemi in my '41. I intend to go with a SB Mopar engine. I would like to have a transmission and rear gear combination that would give me nice street performance and good, comfortable highway cruising rpm's. I also want it to be relatively straightforward to install, i.e. no complex handmade linkages, simple handmade linkages are ok.

I've read threads on A518's, 700R4's, Tremecs, T5's, 727's et. al. I've also read threads on 9" Ford rears, Dakota 8.25 rears, A body 8 3/4 rears, et. al. I really have no preference whether I go manual or automatic at this point. If the stock clutch linkage can be adapted fairly easily or a hydraulic clutch, I'm ok with that.

So, here is my question. If you were starting from scratch and going to use a SB Mopar engine, what transmission and rear axle would you put in your 41 Plymouth coupe?

[Robert Horne]

If I were to change my drive train, I would buy a donor vehicle, such as a Dakota with the V6/Automatic. Early Dakotas had 5 lug wheels I believe. Buying a whole vehicle and transfering parts is a lot easier and less expensive.

[rockable]

That won't get me the 300-350 HP I think I want, Robert. But, I agree that having a donor vehicle would make it a lot easier.

[dndrodshop]

An "E" body 8-3/4 just about bolts to the stock spring (Pads are 1/2" wider). Been running one since '89'. A 440 will fit if you don't mind moving a firewall.

I'm 6'7" and didn't give up leg room. Ran for several years with a modified low pressure stock radiator before I won a radiator at a Goodguys show.

Still Stock front suspension (upgraded to power rack and power disks) and rear springs have never been off the car.

http://home.roadrunner.com/~dndrodshop

[claybill]

i have 41 coupe with 318 '79 baracuda. auto trans and rearend from '79 aspen wagon..2.73 x1 ratio.

on the other hand..i have as much fun and power with a fresh hopped up 'six'

as with the v8. i guess i would just work with the stock motor and up grades

if i did it over again..

v8's have a great ROAR!!

bill

Edited June 5, 2010 by claybill

[Frank Elder]

An "E" body 8-3/4 just about bolts to the stock spring (Pads are 1/2" wider). Been running one since '89'. A 440 will fit if you don't mind moving a firewall.

I'm 6'7" and didn't give up leg room. Ran for several years with a modified low pressure stock radiator before I won a radiator at a Goodguys show.

Still Stock front suspension (upgraded to power rack and power disks) and rear springs have never been off the car.

http://home.roadrunner.com/~dndrodshop

Don't you have the cuda sway bar too/

[Andydodge]

Rock, speaking as someone who has had a V8(318 poly & cast iron auto) powered 1940 Dodge Sedan since 1973 I'll add my 2cents worth.....If I were doing the job again and was young & silly & had the time & money to put into it I'd get either an LA 318 or 360, get it rebuilt including a good balance job, as for gearbox this comes to personal choice but a either a manual or auto so long as it has a good overdrive setup would work, as for steering & brakes, I'd upgrade to 4wheel discs on the original rebuilt front suspension with an upper shock mount relocation, heavy duty sway bar, either a rack & pinion or depending on clearances which with a small block based engine should be o/k, I'd look for a late model steering box that could fit and use the original tie rods etc, rear end would be a 9" Ford which while might go against the grain is cheap, reliable, easily rebuilt and can be geared to whatever ratio you want plus rear disc brakes are a no brainer, redo the rear shock setup by putting a crossmember in and mounting the shoucks angled in as per most cars...rear springs may bave to be changed if this shock relocation is planned or at the very least different spring hangers ........after all that then the rest is again your choice......lol......as mentioned.....my 2cents worth.......andyd

[rockable]

I should have mentioned that I have completely rebuilt the front end, chopped a round off a set of new springs, installed shock perches and shocks and disc brakes. I've also installed the ECI dual master cylinder set up, put new wheel cylinders in the rear, replumbed the brake system, installed new rear shocks and rear springs.

My original plan was to just drive it a while but as I started tackling the 6v electrical system, I stopped and asked myself, "Where does this end?" I could almost as easily go ahead and convert to 12v but I don't want to buy a generator and starter and God knows what else that I'll eventually not use.

That got me to thinking about going ahead and doing the power train. I will definitely use an LA engine. I'm there.

The installation of the rear is pretty straightforward, no matter whose you use and the choice seems to be based on track width, ratios and availability.

I've read that the A518 is a pretty large transmission and will require floor mods. (not a big deal but not something I really wanted to do right now) I know a lot of people run 700R4s, regardless of engine choice. The 700R4 seems to be an easy to install and set up option. I don't know what sort of challenges I'd have with a manual.

I'm just trying to sort it all out. Buying a donor vehicle, if I could find one that had a complete drive train seems like a good idea, too.

What year did the Dakota go away fromt the 5 X 4 1/2 lug pattern?

Thanks for your inputs.

Edited June 5, 2010 by rockable

[james curl]

I am using a 90 Dakota rear end with a 3.55:1 ratio. I had to replace the spring pads. Start to finish, remove the old rear end, cut off the spring perches from the Dakota rear end, install the new perches and roll rear end under car, bolt in the rear end and hook up the brakes in less than six hours. The Dakota rear end has small very wide brakes. Some Darango's have disc on the rear and I believe that they use the same rear end also. Tim Adams said that the bigger brakes from the 70 MoPars would interchange, you would have to ask him which ones fit.

[Robert Horne]

Here is my donor vehicle, 1995 Ford Ranger. Paid $127.00. V-6, Automatic, AC works good. Plan on using this with my 37 Coupe, or 37 2dr sedan.

[Don Coatney]

Here is my donor vehicle, 1995 Ford Ranger. Paid $127.00. V-6, Automatic, AC works good. Plan on using this with my 37 Coupe, or 37 2dr sedan.

That looks like it should work well. Should be a fun project.

[Fireball]

Tough question I must admit. It's so much up to personal preferences, and what is a "big" task and what is not. That varies with peoples experience, but nevertheless swapping the whole drivetrain is not a snap and will require a lot of work. Could be well worth it or then not. Anything is doable but it really is up to individual whether it makes any sense.

What caught my eye is that you consider modifying the floor for A518 something that you are not willing to do. That could easily be the easiest task along the whole project...

I recently put modern MPFI V6 with 5-speed standard and jeep rear in my '46. Lots of custom fabrication was needed, engine mounts, tranny mount, perches, clutch linkage, headers pipes etc. just to mention few. So my recommendation for you is to go with auto tranny, but not with modern RE42 that'll require computer.

Maybe 318 and 4-speed auto out of early 90's ram van? How about Aspen Volare Mirada from late 70's early 80's as a donor car? PM me your email and I'll shoot good instructions for installing LA into these puppys into your direction, someone here passed them couple years ago when I was planning my swap. Those are in word.doc format and cannot be posted here.

Whatever you decide, good luck, it will be fun with V8.

[Young Ed]

My 94 dakota and the 92 I parted out were both 6bolt setups. So you can at least eliminate 92 and newer. A durango may have rear disk but it would be a 6 bolt wheel setup. Also at least for my 94 there are 2 sizes of rear brakes for the dakota.

[james curl]

Tim Adams recommended to me that I could use a '90 or earlier Dakota rear as they were all 5 on 4 1/2" bolt pattern and only needed the spring perches moved to work. He also mentioned that some '70's big MoPar brakes would fit the housing and axle.

[rockable]

Tough question I must admit. It's so much up to personal preferences, and what is a "big" task and what is not. That varies with peoples experience, but nevertheless swapping the whole drivetrain is not a snap and will require a lot of work. Could be well worth it or then not. Anything is doable but it really is up to individual whether it makes any sense.

What caught my eye is that you consider modifying the floor for A518 something that you are not willing to do. That could easily be the easiest task along the whole project...

I recently put modern MPFI V6 with 5-speed standard and jeep rear in my '46. Lots of custom fabrication was needed, engine mounts, tranny mount, perches, clutch linkage, headers pipes etc. just to mention few. So my recommendation for you is to go with auto tranny, but not with modern RE42 that'll require computer.

Maybe 318 and 4-speed auto out of early 90's ram van? How about Aspen Volare Mirada from late 70's early 80's as a donor car? PM me your email and I'll shoot good instructions for installing LA into these puppys into your direction, someone here passed them couple years ago when I was planning my swap. Those are in word.doc format and cannot be posted here.

Whatever you decide, good luck, it will be fun with V8.

Fireball, thanks for the input. Fabricating a new floor is not out of my skill range, I'd just prefer to do it when I do the frame off in a couple years. I've got another frame off project, '64 Catalina, that I really need to reassemble before I disassemble this one. I'm just trying to get it to where I can drive it to local cruise-ins and stuff reliably and be able to see in the dark.

[GaryPrice]

I got a really good deal on a 318 Magnum long block. Going to convert it to a carb setup. I think with a little trimming on the mounting bracket, I'll be able to use the stock serpentine pulley setup. I bought an Explorer rear with disk brakes and I'm using the Cavalier rack. I checked measurements and it looks like a 67 Mustang radiator is a good match also.

I hope to get it all together in the next few weeks. I'll post some pics of it all when I get it together.

[Fireball]

Rock the instructions are in your email, and sorry if you thought I'm suspecting your skills, no way, it's the language barrier if my post was put like that. I just ment that I had to wrestle the most with totally other things than I originally was thinking could be the culprits in my own setup. The hardest parts went smoothly and easy ones were surprise surprise not easy at all.

[Plymouthy Adams]

I only recommend that a mopar be mopar..ie brand for brand...if you cannot do the work and have to have a kit from someone who has been there before...well, whats the point..where is the fun...I will admit to my slight narrowminded view on this subject..but as for upgrading drivetrains..your car..go for it..as much as I hate to see brand x implants..go for it..at least you doing something to either put it on the road or at least prolong its eventual demise

Edited June 5, 2010 by Tim Adams

[rockable]

Tim, in general, I agree with you. The last thing I would want to do is put a SBC in my Plymouth. I'm going to have Mopar power. I might compromise on the tranny, however, since it's not easily seen and there are some better mousetraps out there.

Fireball, no offense taken. I've been doing this a long time, just not with Plymouths. Thanks for the information.