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Need advice on swapping 4speed for my 3speed
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Posted by: RCowan99SSConv

The 66 Valiant is now seeing a lot of interstate miles at 80-85mph on my new commute. This is getting old as the car is wound out pretty good at that speed and gas mileage sucks. This car needs an overdrive!

Which trannies will swap in easily? The car has a 3 on the tree (A903) but I'd consider 4 in the floor. My rear gear is a 2.91 or so, but it still revs more than it should. 1st gear is useless.

As always, any help you guys can give is greatly appreciated!

Posted by: Jopapa

I'd also like to swap out the auto in my friend's '70 Dart with a 4spd manual. The auto seems to be in okay shape (needs a fluid change though), so I'll hold back on any tranny work until it's actually needed, then I'll get ready for a conversion.

Posted by: An11SecRanger

I like the Tremec for durability and cost. I don't know how much you want to spend, but if you intend to get a new tranny, I'd check into a Tremec.
I'd start at ...
Forte's Parts connection

Posted by: Penske

The perfect tranny would be an A833 from a late 70's-early 80's Dodge truck. It's a 4-speed, with 4th being a .73:1 overdrive. First gear is pretty granny, but with a 2.91 it should be OK. Probably a pretty good drop from 1st-2nd, but that OD 4th will be great on the highway. Probably pretty cheap, too.

Posted by: RCowan99SSConv

That sounds like what I need, Penske. Didn't those come in A-bodies also? With a shorter tailshaft or something? It would be nice if my driveshaft would still work, but i guess i could pull both at the same time from the donor.

Posted by: Penske

It says: "1975-1979 A-bodied, F-bodied, 1975-1987 trucks/vans, Aluminum or Iron case" (newer trannys were aluminum)

Might be easier to find a truck since they were used longer. I think you have to have a funky shifter because the OD gear is actually on the 3rd gear shaft.

Posted by: MadScientistMatt

The A-833 overdrive is a pretty common transmission in Aspens and Volares. You may be able to reuse your old bellhousing as some of the 3-speeds came with bellhousings drilled for both kinds of transmissions, but not all of them did. The transmission itself is the same for all engines, but slant sixes have a unique bolt pattern, presumably to prevent anyone from installing a slant six version of the 904 behind a V8.

You may also need to do some hammer and weld work on the floorpan to accomodate the shifter.

Posted by: RCowan99SSConv

Ok.. i have located a 76 Dodge Ram pickup and a 77 Dodge Ram pickup locally, both for under $500 for the whole truck :roll: . Both have a 4speed tranny, and not 4WD. How can I determine if they are the A833 (pretty sure) and if they have overdrive. Also is the tailshaft different than the A833s in the A bodies? I believe I read where there were long and short versions which was basically just the tailshaft was different.

Posted by: FORMULA DEATH

1st off the aluminum A-833's were grenades for the most part , and it was third gear was the overdrive , fourth was still one to one . If you are gonna use one , at least bush the counter shaft and maybe even get it plugged . On the old Four speeds fourth was one to one same as the third on a automatic . You might want to try getting bigger tires on the rear of your car it will help with the higher freeway speeds a bit .

Posted by: RCowan99SSConv

hmmm if the A833s are that bad, is there a better option? Does my 225/6 really have enough power to grenade this tranny?

I thought about the larger tires, but I don't like the idea of my speedo always reading low :/

Posted by: DODGE_MAIN

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Posted by: DODGE_MAIN

The aluminum case A-833 is a "grenade" compared to the iron cased A-833... Which is indestructable!!! They don't call it the CRASH BOX for nuthin!

You will have no problem with that aluminum A-833 unless yr planning on sittin it behind a big power motor and doin some Ronnie Sox 'rowin the shifter' imitations!

Posted by: RCowan99SSConv

kewl

Posted by: FORMULA DEATH

All four speeds are " Crash Boxes " . I have grenaded two in my Barracuda alone , while wasting a perfectly good McCleod flywheel clutch pressure plate combo worth over $500 bucks . Just ask what's in The Haze and you will hear the magic word " Lenco " . The aluminum one should should be fine backing up a leaning tower of power , though you should still bush the counter shaft something I do on my cast iron ones also . Also I have it from some reliable sources that Sox used a Top-Loader , though he would never admit it .

Posted by: MadScientistMatt

There were two lengths of A-833. The A and F bodies used a shorter one; B and E bodies - and I think the trucks - used the longer one.

Posted by: FORMULA DEATH

The B, E , D and C's all had a longer tailshaft than the A's ( don't really know about the F's ) you can tell by looking at the shift boss on the tailshaft .

Posted by: MadScientistMatt

Oh yeah, one other way to tell the long and short 833 apart is that the long one has two triangular shifter mounting points on its tailshaft. The short one only has a single mounting plate.

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