slant six 3sp. to 4 sp. conversion

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540demon

540demon

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hey...this is my first manual trans a-body. its a 74 duster 6cyl with a 3 sp. manual trans. im going to use this as a daily driver,and would like to change out the 3 sp. for a 4 sp. is there anybody who may know if there were 4sp. 6cyls.? what years? im guessing a small block trans wont work...but dont know for sure. any info yall can pass along would be appreciated!

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Small block trans will work. It just requires a slant bellhousing/flywheel/clutch. Probably the best 4 speed for a daily would be the 833 OD. Should be able to get that out of a mid '70's A or F body. Lots of trucks came with it too, so you may want to check slant 6/4 speed trucks for a bellhousing, flywheel, etc. There is a lot of good 4 speed info here http://www.bigblockdart.com/techpages/4sptech.shtml.
 
540demon said:
my 3 speed bellhousing wont work?
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Yes, it should if it is the dual bolt pattern. Forgot about that. I did the 3 speed to 4 speed swap last summer in my Scamp. So pretty much all you need is an A-body or F-body trans and probably a different length driveshaft.
 
thanks for the input...i guess if a smallblock trans will work,it may be easier to find one.i'll start diggin around! thanks again!!!!!!
 
What do you call a 3 speed standard if the 4 speed is called a 833
 
wish4hemi said:
230 I believe, could be wrong though.
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Depends on the year. In the 70s, A230 was the most common, was fitted to either slant 6 or V8 cars. My 73 Duster had the light duty A250 version, labeled in the manuals as "six cylinder only". After the transplant, it lasted several years behind a gently driven V8, finally tossing all the input shaft bearings on the ground in the middle of a nice red puddle.

The 1960s used different numbering, can't recall exactly and my books are all packed in storage right now. But you're not likely to find many 3-speeds left anymore, anyway.

- Erik

64 Valiant, 170 3-spd
82 Volvo wagon, 5.0 5-spd :)
 
In a 74 Duster the standard 3 speed manual was the A-230......which is easy to identify due to the inspection cover on the side as compared to the A-250 that is a toploader.
 
I have a few of those 3 speeds left if anyone needs em,and the specific bellhousings that wont work with the 4 speed....got them too :cheers:
 
540demon said:
my 3 speed bellhousing wont work?
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When I did the swap in my 68 Barracuda the threes speed bell housing didn't have the bolt pattern for the 4spd and wasn't deep enough to drill and tap for it. If the mounting surface on your bell doesn't extend below the 3spd housing and have an extra set of threaded holes below the 3spd then you will need a new bell housing.

I used the A833OD 4sp from a \6 81 D100 pickup. That bell housing had both patterns. The truck A833OD has a longer tailshaft than an a-body but otherwise fits. You will need to fab an adapter for the shifter to have it come out in the correct location and you will need to shorten the drive shaft. The bigblockdart.com page previously mentioned has a whole right up on using the long tailshaft tranny in an a-body.

What ever tranny you use will also require the slip yoke from a 4sp or 727 car. The output shaft is larger than the 3spd or 904.
 
i appreciate all the info guys!!!i may just leave it alone and run what i got 'til it dies! i was hoping it would be a little more straight forward of a swap.
 
540demon said:
i may just leave it alone and run what i got 'til it dies!
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That'll probably be awhile... ;)

Hey, at least you already have the floor shifter in place, so a swap is relatively easy. Whenever you do finally get tired of the 3-spd, and find a 4-spd or even fabricate mountings for a 5-spd... keep us old 3-on-the-tree lovers in mind (in other words, someone might want the 3-spd box).

1970s 3-spd units are more desirable (relatively speaking) because they have all forward gears synchronized. My 64 is a reminder of the old days, when people used to *need* to come to a full stop before engaging first gear. Other than historical relevance or sparking conversations with Graybeards, or providing a fairly unique chance to practice double clutching while rolling, that characteristic has little else going for it. Installing a 70s 3-spd into a 60s car is *almost* a bolt-in affair, except for needing to lengthen one of the shift rods an inch or two. Someday I might do that, if the current 60s unit ever grenades.

But I wouldn't trade my column shifter for a floor mount, no way. It's way too unusual these days, despite that it used to be as common as oatmeal for breakfast. I do sometimes wonder how I could install an overdrive, but then I decide over and over again that a GearVendors unit isn't really worth it. Maybe when I'm rich and famous I'll do it anyway...

- Erik

64 Valiant, 170 3-spd
82 Volvo wagon, 5.0 5-spd :)
 
>>Thead Hijacking Starts<<

OK mpgFanatic.....
I have a 1974 3 speed column shift tranny I will make ya a deal on! It is currently being used as a doorstop. PM me if you are interested.

Later,
Bruce B.

>>Thread Hijacking Ends<<<
 
Whoa guys! The 4-speed was available behind the 64-65 /6. It had a lower first gear than the V-8 transmissions. It would fit the same bell housing as the 3-speed manuals.

The 4-speed didn't show up behind the /6 until 75 or 76, and then in OD form. The 833 OD has a larger front bearing that requires the newer bellhousing to go along with it.

A Hurst Competition Plus for the A-body works fine on the 833 OD. Just remember to reverse the 3-4 lever on the transmission.
 
2 Darts said:
Whoa guys! The 4-speed was available behind the 64-65 /6. It had a lower first gear than the V-8 transmissions. It would fit the same bell housing as the 3-speed manuals.

The 4-speed didn't show up behind the /6 until 75 or 76, and then in OD form. The 833 OD has a larger front bearing that requires the newer bellhousing to go along with it.

A Hurst Competition Plus for the A-body works fine on the 833 OD. Just remember to reverse the 3-4 lever on the transmission.
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Yeah.... What he said!

Later,
Bruce B.
 
2 Darts said:
Whoa guys! The 4-speed was available behind the 64-65 /6. It had a lower first gear than the V-8 transmissions. It would fit the same bell housing as the 3-speed manuals.

The 4-speed didn't show up behind the /6 until 75 or 76, and then in OD form. The 833 OD has a larger front bearing that requires the newer bellhousing to go along with it.
Click to expand...

My 68 Barracuda was orignally a \6 3pd manual car. The bell housing definately would NOT accept a 4spd tranny. The bell housing only had one bolt pattern and there was not even enough surface area to drill and tap for the larger bolt pattern of the A833.

The bell housing I wound up using (along with the A833OD) was from an 81 D100 pick-up that was a \6 and A833OD. This bell housing had both bolt patterns.

I can't speak for the early a-bodies or the later cars but my car had a bell housing that was definately only for the 3spd manual tranny.

There are a couple of approaches to fitting an A833OD to a car that didn't have one with out getting the later bell housing with the larger 5.125 hole.

1. If the bell you have has the 4.180 opening you can replace the retainer on the front of the A833OD with a 4.180 one or machine the one you have.
2. Have the opening on the bell housing machined to 5.125.
 
540demon said:
i appreciate all the info guys!!!i may just leave it alone and run what i got 'til it dies! i was hoping it would be a little more straight forward of a swap.
Click to expand...


It is really pretty straightforward, and not too expensive, either. I used to have an A833 in a 1982 B150 van, and that thing hauled ALL SORTS of weighty items and never complained. It was also a MONSTER in the snow....the gearing was pretty good.
It's worth the effort, I think. I'm going for it if I manage to get my '73 done soon (big block conversion)....that will be one of my future projects. Slanties are a lot of fun.
 
you wont be happy with a 4 spd..you will prob be shifting even more..due to gear ratio.... You would prob wanna chage rear axle gear to make it fun to drive...but after all that..you might as well just v-8 the car...
 
I have swapped in a 4 speed into a slant 6 narrow body Dart. You will need to acquire the "4 speed hump" to weld onto the tunnel of your car, if you have not done that yet. I see that you have cut the floor to install the shifter for your 3 speed. Unless you have installed the wider hump, the tunnel will be too narrow for an A-833. You will also have to cut two holes on either side of the brace. You can bolt in the 4 speed hump, but it is probably better to braze or weld them in.

I believe that the 273 A-833 transmission is the same as those used in early slant 6 cars. I used the overdrive, but it is a very weak transmission. Mine failed twice under moderately aggressive use. I would avoid the OD Trans, if at all possible. Anyone who can find a 273 A-833 has a great transmission for the slant 6.
 
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