Manual transmission swap

-
PepperoniOlive

PepperoniOlive

Member
Joined
Jun 18, 2024
Messages
6
Reaction score
2
Location
Imperial, MO
I have a 73 dart with a 360la and 904 transmission. I would love to swap to a manual but I’m not sure which one would be an easy swap and easy clutch system. I don’t have or need a lot of horsepower. Just a cruiser at this point.

What do you guys think?
 
There's a balance between "easy" and what your budget is. The easiest option will likely be the most expensive
Also, what do you want? As close as possible to original (4-speed) ? Or do you want a 5/6 speed
The absolute cheapest might be a mopar 3 speed swap. You can get the transmission itself for peanuts
 
Just as a general FYI... I'm in the process of an original style 4 speed swap. I've been collecting parts for a couple years
Junkyard a833, swap meet aluminum bellhousing and pedals, new clutch/flywheel. I have some other parts that may or may not work. I will find out once the big parts are in the car.... I'm about $1,000 deep so far and counting.
The junkyard trans alone with shifter and shifter rods was $500... prices are crazy around here
 
there's a lot to unpack here...

the "easiest" swap is all stock. everything fits like it's supposed to, all the parts are out there, there's a FSM to guide you, lots of people have 'em and can answer questions if you get stumped.

however you'll need to go track down all the bits to make that happen... which if you wanna fire up the computer and melt a credit card is an easy button. but if you're not finna drop like $3,000 then it's online classifieds, dealing with CL/offer/MP whack-a-doos, trawling the yards and swaps. and you'll get a used set up together for probably about 2K all said and done.

another option would be a 5spd swap. which, is pretty much the same level of action but add 2+ grand to a new set up from a vendor and probably like 1,500 to piecing together a used setup; then add a level of complication for non stock things and stuffs. but that's a path that's been forged and well traveled, so it's not like you'd be out in the wilderness all alone.

to note, here's a few considerations you may not have thought of: you'll need to cut/modify your floor. which is nbd if you're rolling around in a beater, but if you've got mint interior is kind of a pita. you'll need to modify your exhaust, which if you're not there or haven't tackled that yet is no big whoop, but if you just dropped a grip of dough on headers or pipes you mighten maybe be revisiting all that. if your crank isn't drilled for the 4spd input shaft you'll need to sort that out. and shorten your driveshaft.
 
My advice is go with the Malwood pedal and hydraulic bearing. It works amazing, is wayyyy easier to install. Pricey but worth it
 
I just recently did a 4spd swap in my 68 Dart that originally came with a 904. Upside is you can reuse the same driveshaft since it’s the same length as an A833. The rest though, it was a challenge for me since it was my first time doing so.. I went off internet research on here, videos on YouTube, and my natural mechanical ability..

It was more expensive of course than just buying say a TCI trans that’ll drop right in but I wanted a 4spd. Where I live, there’s no resources that I’m aware of and I don’t know many mopar guys around here that would have a stash to buy from so I had to buy over the internet. I bought a 4spd setup from a shop that pulled it to convert it to an auto so it had the bell, trans, linkage, shifter, fork, flywheel, clutch, some of the pedal linkage.. I sourced the rest from Brewers. I had a buddy help me that knew nothing about these cars and it took about 2 weekends. Which wasn’t bad considering our experience level with the project at hand.

I lucked out and my crankshaft was drilled deep enough to accept the input shaft. I used the later roller bearing that goes into the crank register. I didn’t measure the ID to see if a bushing would work, I went straight to the bearing instead.

The pedals was the longest project of it all. I didn’t pull the column which would have made it easier. I didn’t pull the whole pedal assembly. You can remove the brake and replace it with the smaller pad one and add the clutch pedal to the exiting assembly. I spent the better part of 4hrs wrestling that since the quarters are so cramped. I hope I never have to 4spd swap another car again lol.. but if I do, I’ll have much better foundation of knowledge should that ever happen.

Best advice I can give is if your patient, can swing a wrench, and like a project… give it a shot, it’ll nickel and dime ya more than ya think.. overshoot your budget.. I did and I managed to cover it all. Now if I had some local buddies that were well versed in this plus a local source for parts, it would have been a little less of a pain.
 
PepperoniOlive said:
What do you guys think?
Click to expand...
Why?
The 904 has a torque-convertor, which is a TOTQUE-MULTIPLIER;
that is like an infinitely adjustable device
that automatically shifts from as much as 2.0:1 to as low as 1.03
depending on the torque going thru it.
Typically you can expect a ratio of 1.8 at zero mph. That makes the 904 act as if it has nearly doubled the rear gear. Say you have 2.76s; at WOT, this could take off like it had 4.97s, then automatically, as the car accelerates, spool down toward 1.1 at top speed, shifting up or down by itself, as torque input varies, and speed changes. .
Swapping to a 4-speed manual; you won't get that, and with the same rear gear, the car will be lazy.
To get some of that TM back you will need to increase your rear gear. ............
which will increase your hi-way cruise-rpm.
If it was me, as in what do I think;
I'd just get a higher stall TC, and install a semi-auto shift kit in the 904.

But hey, if you just want a manual trans for the sake of having it, I understand that, cuz I have been into that same mindset for over 54 years.

For you, I recommend the AX-15, cuz it's a 5-speed suitable for a modest torque engine, and has an overdrive.
The AX-15 ratios that I have on file are
3.83-2.33-1.44-1.00-.79.. IIRC there are some other ratios.
This will work excellently with a rear gear of 3.23 (65=2200 with 25.5 tall tires.)
If I had a modest 318/273, or maybe a lo-torque 360 ; this is the trans that I would use. Adapters are available. Some fabrication is involved.
Diaphragm clutches have a modest leg-power requirement, I love mine.
If you just want to bolt it in, any fully-synchronized Mopar trans is a no fuss install. I and several others on FABO, have complete or nearly complete kits, and I think Dan Brewer as well.
Generally, it will not be cheap.
You might be interested in a the Commando/GVod I have in stock. It will make your 360 come alive.
There is nothing I would rather have.
But I ain't giving it away.
 
AJ/FormS said:
Those must be Pre-Covid prices, lol.
Click to expand...
nah, that's about right for current prices around here.

i just pulled a complete OD box and it was a hair under $400 so if you add in a shifter and linkage you'd be clicking right at 5

but pickin's is slim at the yard and it's more about luck on those than anything else. the chances of finding a standard 833 are darn near nonexistent. swap and classified prices are astronomical, as per usual.
 
Projectile Dart said:
Just as a general FYI... I'm in the process of an original style 4 speed swap. I've been collecting parts for a couple years
Junkyard a833, swap meet aluminum bellhousing and pedals, new clutch/flywheel. I have some other parts that may or may not work. I will find out once the big parts are in the car.... I'm about $1,000 deep so far and counting.
The junkyard trans alone with shifter and shifter rods was $500... prices are crazy around here
Click to expand...
When? 1990?
 
My $500 got me this...

20200823_130236.jpg

and This was $1000 later...

20220618_192447.jpg
 
OD boxes are probably easier to source and cheaper to buy as they’re not as desirable as the 1:1 box. A 400hp rated diaphragm clutch from McLeod is around $250 bucks plus the cost of a 360 compatible flywheel as they’re externally balanced.. I spent more than some since I replaced stuff with new items like the starter for a later model dodge ram unit..way smaller and cheap. New U joints on the driveshaft at both ends. You’ll need a 30 spline yoke to match the 833 as the yoke for the 904 is 26 spline. Biggest road block you’ll likely run into is that the crank may not be drilled deep enough to accept the input shaft of a 4spd. The easy remedy is to knock off the tip of the input shaft. Some are okay with that method. Others would have the crank drilled which is another can of worms to open. Thankfully I didn’t have to do either with my 68 318.

I also had to clearance the crossmember for the 1-2 shift rod to clear.. just one of many details that I learned along the way
 
AJ/FormS said:
Those must be Pre-Covid prices, lol.
Click to expand...
This is the current price list of my local Junkyard, and those prices have doubled at least since covid. I got charged separate for the trans itself, each of the 3 shifter rods reverse light switch, the shifter, the shifter handle, and the shift knob. All in all it was over $500 after taxes plus a day and a half of work in the dirt. I got it about a year ago.
It was worth it because the going rate for a similar condition one i see online is usually about double. Unfortunately it was an early A with a busted 318 that had a 273 bellhousing on it so I couldn't get any more parts off it. Took me years of waiting before I finally scored the trans.

Screenshot_20241102_152750_Chrome.jpg
 
You must log in or register to reply here.
-

Back
Top