A833 OD or 727 behind a 440. Suggestions and questions

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my5thmopar

my5thmopar

Life Long MOPAR Owner
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I'm picking up a low compression stock motorhome 440 engine for my D100 project. It is coming from a another D100 and I'm getting the complete setup. The 440 has a 727 with it but, I have a 86 A833-OD from a truck that had a /6. I also am getting another BB bell for the 440. I already have a new 10inch flywheel and clutch set from the /6 and can get a hydraulic throw-out bearing. Will the /6 clutch stuff work on the 440? I just can't decide which way to go. I know the manual has the "cool" factor but, a 727 might be stronger and/or easier. I have several gear sets in my stash. My truck has a /6 with A745 3-speed I'm pulling. What ya think? Thanks Craig Mods move if this needs to go in another section.
 
my5thmopar said:
I'm picking up a low compression stock motorhome 440 engine for my D100 project. It is coming from a another D100 and I'm getting the complete setup. The 440 has a 727 with it but, I have a 86 A833-OD from a truck that had a /6. I also am getting another BB bell for the 440. I already have a new 10inch flywheel and clutch set from the /6 and can get a hydraulic throw-out bearing. Will the /6 clutch stuff work on the 440? I just can't decide which way to go. I know the manual has the "cool" factor but, a 727 might be stronger and/or easier. I have several gear sets in my stash. My truck has a /6 with A745 3-speed I'm pulling. What ya think? Thanks Craig Mods move if this needs to go in another section.
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I ain't going to beat around the bush here whatsoever. if it's a daily driver, put an automatic in it. if it's your hot rod, go with the 4 Speed. My-2.
 
yellow rose said:
I don't think you can use a 10 inch FW on a big block.

I'd use the stick. I always use the stick.
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You young 39 year olds can still handle those stick shifts for daily drivers, but us old men like an automatic. I just don't like that stuff they put inside of them automatic it gets all over me and the floor and everything I own and I hate it and I don't use the word hate much.
 
Just put something together, summers coming! Watch out for the depth of the hole in the back of your 440 crank, may not accept a standard trans input shaft.
 
If that 440 ever hooks the tires up good, that OD transmission will be your weak point.
 
RustyRatRod said:
If that 440 ever hooks the tires up good, that OD transmission will be your weak point.
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Agreed, then there's that too, if it's really the hot rod hot rod and that's the choice between the two? then the 727 again is the better choice.
 
I have a 69 440 in a 1980 D100 step side with an 833 OD.

It is super fun and super easy to drive.

First is awfully short (but so is my 2015 jeep Renegade 6 speed), and I spend a LOT of time in second. There are also a larger number of 2-3 shifts, which are the "power" shifts.
That should be taken into consideration as well.
 
Might be worth asking who's got experience putting the overdrive automatics in behind that motor. Takes adapters to use the Chrysler transmissions but overdrive is righteous.
 
I could be wrong, but I have heard that the 727 auto transmissions in motorhomes will not work in cars. I don't remember why,.... It had something to do with the tailstock and the driveshaft. All I know is that there are usually issues.

I remember watching the Roadkill episode where they got a 440 out of a motorhome and couldn't use the transmission from the motorhome on that one either. They had to get a different one because it wouldn't work in the '68 Charger they were building. Seems to me they picked up a beater Fury or Monaco or something to pull the transmission and other parts out of because the motorhome trans wouldn't work.

Here are a couple links talking about that "General Mayhem" build:

The Generals: The Story of Mayhem and Maintenance - Roadkill

 
I think in this case, the manual would do it for me, but not with a performance rear gear. The od gear in that box will not take any shock-loading. So with a performance gear you could easily forget that when banging gears. But the od gear could help the motorhome engine pick up some fuel-economy, if it's idling down the hiway. And the 440 has way enough low-rpm torque that it doesn't need the big-number gear. In this way the big 1-2 gearsplit will be less noticeable. What gear then? That would depend on your tire size. Mostly.
Probably a gear to put the 440 at a favorable rpm at 30mph in second gear.
But what's back there now?
 
A 10 inch clutch won’t even hold a 273, You will have to go with whatever flywheel and clutch that will match your BB belllhousing. Reseal the trans and replace the floating countershaft with a standard one. You will probably need to swap the bearing retainer to pilot into the bellhousing. And remember, don’t Power shift into O/D.
 
The combo is going in a 64 D100. Truck has peg leg 3.91 but, I have 3.23, 2.94 and 2.76. I'm adding a sure grip to one of them. If manual, I would have to get all the clutch stuff and the 727 floor shifter. I think the cost is going to be about the same. The 727 is freshly rebuilt from a car/truck and not a motor home. I do like stomping on the accelerator and my other D200 383/727, gets a lot of it. I'm trying to make the truck road worthy for taking road trips, cruising and such, not driven daily.
 
be careful with the super low 1st with anywhere near low R&P set.

It will turn into a granny real fast leaving you only 3 usable gears.
 
Tire size, man? 3.91 could be fine with tall tires, say 30s.
A 30" tire with 3.91s, would act the same as 3.13s with a 24, or 3.55s with 27.2s, or 3.23s with 24.8s.
So don't panic yet.
While 3.91s are more than the BB wants no matter the realistic tire size, 3.23s could easily be made to work with
IMO, a good starter gear for the big 440 might be about 8/1, corrected to a 24" tire. And that would math out to the 2.94s and 27s;
3.09x2.94 x 12/13.5=8.08, so that is enough first gear. But second is quite far away, and probably will not like that 2.94.
For second I like a 6.06 ratio, corrected to a 24 inch tire.
With those same 27s as above, this would ask for a rear gear of 4.10s
1.67x4.10x12/13.5=6.08, so that is what second wants to have similar performance to a regular 4 speed in second, with 3.55s
1.92 x 3.55x12/13.5=6.06

Now since you already have the 3.91s in there, you could try
3.91x1.67x12/6.06=12.93 and 12.93x2= 25.8" tires, which might look a little odd. Therefore lets go with 28s and see how that works
3.91x1.67x12/14=5.60; and that's a bit of a stretch, even for a 440.... but lets continue.
The ratios in that box are 3.09-1.67-100-.73od.
Lets try it with the 3.91s cuz they are already in there, and with 28s.
Ok so your first gear starter is 3.09x3.91 x12/14=10.35 corrected to a 24" tire. This is plenty of take-off power. So off you go and let's say you pull the stick at 2800. The Rs will drop to 2800x1.67/3.09=1513.... has that motorhome 440 got torque down there? I bet it does. So now you are at 19mph.
So now you boot it up to 30mph in second and hit 2350 has your 440 got torque there? I bet it does. So you continue to 2800@36mph preparing for the shift that will drop the Rs to 2800x1/1.67=1677 Well that would be a long hard pull to 65, so lets drive it up to 48mph@ 3760. Yeah that sounds doable.
So now you shift into direct @ 3760x1/1.67=2250. Got torque? Well not so much now that the truck is starting to push wind. Is it doable? Sure, but not really a performance option. Really, second gear will get you 60@4700. Then into direct, followed by overdrive right behind .
So now you are at 65=2226, a good cruiser-gear, but when will you use direct gear? It's kindof an unused gear. Say the lowest rpm you might want to use direct was 2400rpm; that would be 51mph. And 65 would be 3050.
So would 3.91s work? Yes, but
Yes but,does the od-box suit your driving needs? It's not really a performance combo, yet it requires a minimum first gear rpm close to 3000, to pull briskly in second gear. So a different combo of, tire size and rear gear, might be more attractive. But you can never get away from the,IMO, very wide splits.
 
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I have 245 70 15, which is about 29"
 
Oops forgot tires are 295/40/20 with spec says 29.3 by 11.6. AJ thanks for the math.
 
I wish I knew for sure what gears I have in mine.

Guess I will have to eat the cost of a gasket and check.
 
my5thmopar said:
Oops forgot tires are 295/40/20 with spec says 29.3 by 11.6. AJ thanks for the math.
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That will slow everything down 28/29.3= to 95.6%. Not a real big deal. The point I was trying to make was the wide splits. If the 440 has a low rpm cam in it, then it will pull the splits ok WITH the right rear gear. IMO the 3.91s are the minimum with the 28s. With 29.3, that would now be 4.10s..With this trans, it's all about making second gear happy. I would leave the 3.91s in there and see how you like it.
 
YY1 said:
I wish I knew for sure what gears I have in mine.

Guess I will have to eat the cost of a gasket and check.
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Actually you have two other options.
The first is to just turn the axles and see how many times the driveshaft turns, and some simple math spits out the ratio.This is dead-nuts accurate.
If you have a SG you just get both wheels up, mark the tire and D/S and turn the tire one exact complete revolution, counting the D/S revolutions as you go. A 3.55 gear would totate the D/S about 3.5 revolutions; a 4.10 would turn a tic over 4 revolutions; etc.
With an open diff, you only jack up one side, and now turn the tire Two full revolutions.

And the second is to do the math at speed versus rpm. This is not very accurate with an automatic, but will usually get you within 10%, sometimes 5%, if your speedO is accurate .
 
speedo doesn't work but back when I was driving it a lot, I used my phone GPS speedo and noted the RPM in 3rd (1:1) at 30, 50, and 60 MPH.

Of course I don't remember now.

One of today's "to do list" items is replace the rotten fuel line for the gas can it's running off of to the electric pump. Of course I have 5/16 line and the can has a 3/8 barb.

Have you priced fuel line lately? Last I bought was about $1 a foot. Now is $3 per foot!
 
Good read, i am doing an A833 O/D setup with my 67. 3.73 gears and 255 60s. Going to be either a warmed over 360 or 410. I hear the o/d is the weak point on a lit of these threads all the time. If that the trans we both want to go with, whats its achilles heal? How do you go about fixing its problem so it can be used and abused without breaking it? I mean i'd prefer a passon A588 but i dont have that kind of money just lying around. Or even a close ratio A833 iron case 4 speed, but living out in BFE makes that **** like that hard to find. I scored my O/D out of a slant sux volare wagon.
 
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