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64 A100. What Auto Tranny?
https://slantsix.org/forum/viewtopic.php?t=45172		 Page 2 of 3
Author:  Reed [ Thu Feb 09, 2017 7:03 pm ]
Post subject: 
I see no reason to put a 727 behind a slant on a daily driver, even one that does a lot of towing or hauling. My 1976 Dodge truck has a 225/727 combination and I plan on swaping out the 727 for a 904. The earlier and lighter A100 truck or van chassis would do just fine with a 904. The slant six 904T actually has a four gear planetary gearset and the same number of clutches as V-8 transmissions.

And the factory adapter plate was dropped in 68 when Chrysler came out with the slant six case for the 727. The adapter is only found in 64-67 A100/A108 trucks and vans. The coolest combination of factory parts is a 225 with the adapter plate mating it to an A500 four speed auto with overdrive.
Author:  Bionic [ Mon Mar 06, 2017 3:05 pm ]
Post subject: 
Quote:
I see no reason to put a 727 behind a slant on a daily driver, even one that does a lot of towing or hauling. My 1976 Dodge truck has a 225/727 combination and I plan on swaping out the 727 for a 904. The earlier and lighter A100 truck or van chassis would do just fine with a 904. The slant six 904T actually has a four gear planetary gearset and the same number of clutches as V-8 transmissions.

And the factory adapter plate was dropped in 68 when Chrysler came out with the slant six case for the 727. The adapter is only found in 64-67 A100/A108 trucks and vans. The coolest combination of factory parts is a 225 with the adapter plate mating it to an A500 four speed auto with overdrive.
It would become very apparent why you have install a 727 in a SWB A100. The transmission cannot exceed 22" in length. The only options for a short shaft are in the 727.
Author:  Bionic [ Mon Mar 06, 2017 3:18 pm ]
Post subject: 
"The earlier and lighter A100 truck or van chassis would do just fine with a 904. The slant six 904T actually has a four gear planetary gearset and the same number of clutches as V-8 transmissions."

wow....again, the A100 truck/van chassis cannot fit the 904 due to drive shaft length limitations. ONLY the A108 van could put in the 904. All in the hopes to gain back a possible...what, 15% (maybe) power loss compared to a 727??? I'm sure the other model trucks in the line would have no issues with the extra 4" of tail shaft that the A100 does.
Author:  DusterIdiot [ Mon Mar 06, 2017 5:13 pm ]
Post subject:  Correct...
Quote:
It would become very apparent why you have install a 727 in a SWB A100. The transmission cannot exceed 22" in length. The only options for a short shaft are in the 727.
Oddly this issue is even noted in the old Carroll Shelby version of the Direct Connection Chassis Manual... LOL....

Although I had heard a rumor at one time that AMC's version of the 904 came with a slightly shorter tailshaft than the Mopar version (not sure if the mainshaft is compatible with the mopar yoke or guts....
Author:  Reed [ Mon Mar 06, 2017 7:50 pm ]
Post subject: 
I stand corrected. Having never owned or worked on euther an A100 or an A108, I was not aware of the lack of space for a 904. However, I stand by my recommendation of a 904 over a 727, provided there is space for it.
Author:  emsvitil [ Mon Mar 06, 2017 8:34 pm ]
Post subject: 
Is the space a hump or driveshaft length problem?

If driveshaft length, I would think you could use high angularity u-joints or CV joints and have a short driveshaft.
Author:  Reed [ Mon Mar 06, 2017 10:02 pm ]
Post subject: 
I do know that a b series van transmission bracket can be adapted to the A series body.
Author:  greasmnky [ Mon May 29, 2017 12:37 am ]
Post subject:  Transmission length
A full length 727 will fit an A100 with the 90 inch WB
I have a full length ( same as a 727 ) 833 OD in my 65 A100 pickup .
have owned 12 A100's and A108's . Not sure where Bionic is getting his info , I have pics if need be .
Author:  a100gary [ Sun Jun 28, 2020 10:40 pm ]
Post subject:  Re: 64 A100. What Auto Tranny?
Is your 833 in your A100 a four speed plus overdrive? Or is fourth gear OD? Also, column shift?
Author:  GregCon [ Mon Jun 29, 2020 2:27 pm ]
Post subject:  Re: 64 A100. What Auto Tranny?
A 904 might have the same number of clutches and planetary gears as a 727, but they are way smaller diameter. There is a relationship fully understood only by the highly educated, and Keaneu Reeves, which speaks to the fact that clutch holding strength goes up exponentially with diameter.

Now, who wanted the short 727....?

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Author:  vitamindart [ Tue Jun 30, 2020 8:08 am ]
Post subject:  Re: 64 A100. What Auto Tranny?
keep in mind the a100/108 trans mount is on the Top. unless you are making a crossmember or a custom mount bracket ( some have bolted to the tail housing bolts ) a standard car trans wont work.
Author:  Reed [ Tue Jun 30, 2020 2:10 pm ]
Post subject:  Re: 64 A100. What Auto Tranny?
Quote:
A 904 might have the same number of clutches and planetary gears as a 727, but they are way smaller diameter. There is a relationship fully understood only by the highly educated, and Keaneu Reeves, which speaks to the fact that clutch holding strength goes up exponentially with diameter.

Now, who wanted the short 727....?
But is the added clutch holding strength (a) necessary and (b) worth the tradeoff in overall drivetrain efficiency over a 904? I stand by my assertion that in most applications there is no reason to put a 727 behind a slant six.
Author:  GregCon [ Tue Jun 30, 2020 2:42 pm ]
Post subject:  Re: 64 A100. What Auto Tranny?
I agree, the 727 is overkill x 5 for the average Slant.
Author:  69a100 [ Wed Jul 01, 2020 8:45 am ]
Post subject:  Re: 64 A100. What Auto Tranny?
Quote:
I stand by my assertion that in most applications there is no reason to put a 727 behind a slant six.
Well there obviously is, otherwise Mopar wouldn't have done it now would they???
Author:  Reed [ Wed Jul 01, 2020 9:22 am ]
Post subject:  Re: 64 A100. What Auto Tranny?
Quote:
Quote:
I stand by my assertion that in most applications there is no reason to put a 727 behind a slant six.
Well there obviously is, otherwise Mopar wouldn't have done it now would they???
Yes, but the reason most likely wasn't because of concerns for longevity or technical necessity. My 1976 D100 was built with a 225 and a 727. But that was because Dodge did not offer 904s in any trucks or vans that year, no matter the engine or package ordered. Just a few years later in the early 80s Chrysler was putting 904s and 999s behind smallblock engines in trucks and vans without any significant changes in the design of the engines or transmissions.
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