A833 aluminum case with OD strength?

I had a 77 Aspen RT with four speed OD behind the 318 about 30 years ago. Seemed like a decent transmission but he motor had no balls. I've seen where folks have adapted E-body tailshaf housings onto the aluminum case A833 OD transmissions. Do these have the strength to live behind a 400-450 lb-ft motor? Really just a three speed with an extra gear isn't it. 3rd is 1:1?

The A230 is a cast iron 3-speed & it was available behind 383 HP engines.

It skips the 4th shift which just takes more time. ;-)

3rd will live fine because it is straight thru the trans, 1-2-4 run on the countershaft and will eventually wear out. If you dont beat on it and use gear oil it will live a while.

You also can take the guts out of the transmission and transfer to a cast iron housing if you want. These also where in trucks. If maintained it will do fine.

Im not up on the 4 speed od AL trans but im wondering what wears out, maybe the end of the case? If so im running what was a DC al 4 speed that I think had a nice bushing, ect in the al case. I might have pics prior to install.

The cluster shaft pin wallows out the case and the gear mesh opens up causing failure. You can have the case bushed at both pin ends for more strength.

Yup. I had an aluminum case that was bushed. Just as good as an iron case but less weight.

I have a DC AL case with OD internals in my Sixpack Shaker Challenger - I would think it would be fine

We ran one once & no issues tho circle track ain't a drag race start. 1st was synchonized. (2) different ratios available iirc. one came behind a /6 & the other a small block V8 app.

I had an iron case OD built by Jamie Passon behind a 408 it was super fun. The close ratio I always hit 4th and wanted another gear

I've been inside of almost every type of NP833 trans built for Mopar since 1964 23 and the 18 spline HD Hemi/440 trannys. up to the latest versions of the NP833 OD
I have both versions of the NP O.D. tranny in the shop, one A body type like you had and two of the bigger van and pickup types that look identical to the 1970 and above B and E body trannys except the main case is aluminum like the A body are and they kept the longer cast steel tail shaft like the 1970 to 1974 B and E bodies came with stock with both shifter mounts.
I put one out of the van/ pickup type O.D. trannys in my 1966 Dodge Coronet Deluxe street car I built, I will NOT beat on it very hard after seeing the gears inside
IHTHs

If you use a steel case, good lube, it will be fine.. just don't cowboy shift 4th, or tow a heavy trailer in 4th.

Dodge added clearance between the case and countershaft on the aluminum case. When you shift, this clearance allows the countershaft to beat the case countershaft bore out of round. I'm putting one in my Charger, if I like it I will either bush the case or use an iron case. Mopar Muscle had an article named Carrying the big stick, where they bushed an aluminum case.

Not the article you mention, but Steve Dulich explains the bushing job in this one.
https://www.hotrod.com/articles/mopp-0110-a-833-aluminum-case-buildup/


Opinions seem to go both ways. One guy says he sees cars with these OD's lift the front wheel and the next guy wouldn't put one behind a slant-6.

I have the original article if interested. Someone once posted when they went to the track they raced in 1,2,3 and drove home in 4th. I bought mine for $25 and had the input collar cut to 4.81 for $15. If the transmission is good and I like the gear splits I will keep it. If not I still have the 18 spline. Someone told me last summer that Jamie Passon bushes cases.

I'd like to see the article if you could scan it. I didn't do as well as you at $25 but I didn't do too bad for a complete setup from the flexplate back, minus the shifter.

Any machine shop can put a sleeve in the case. People call it a "bushing" but in reality its a steel sleeve you want in there. Personally, I've had a few of those cases including an original DC race case that had the bolt flanges and a few other places beefed up. But I'd never put one behind a high HP motor. Guys can tell you all the good luck they've had with theirs but its the bad luck with yours that really matters. Why take the risk for 10 pounds of weight savings. If it means that much do you, go on a diet.

FWIW its understandable why Dulcich would run this case. a) he gets a grand for the published article and b) he runs his car in a class where every little bit counts - even if it only survives the weekend.