auto to 4 spd OD swap

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Jkirk

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I'm looking for information on installing a manual 4spd OD into a 65 Barracuda. The current transmission is a 904 atuo that is has a high pitch whine from front pump area.

Stock 273 with 2 bbl GM TBI system 2.73 rear end and 14 rims.

Looking for best fuel mileage and the least amount of problems down the road.

I'm not wanting to drag race.

I'm looking at a Hydraulic clutch system.

What clutch dia should I look for?

The donor car should be a Aspen or Volare for a short tail shaft is that correct?

What bell housing do I need to find?

What improvements should I do to the Al trans?

I know that drive shaft must be modified.
 
All of the OD units are short tails. If you can, get all of the pieces from a Volare/Aspen, and then buy stock replacement clutch parts as needed.
Hydraulic clutch? as in a slave or hyd T/O bearing? The hyd T/O bearings are very expensive.
You will need to replace the rear gear. In OD your final drive would look like a 1.9... To maintain your 2.73 final you will need a 3.9 to start.
 
I'll see what I can do here.

As far as a clutch, you're probably going to want a 10.5" for the 130 tooth flywheel.

The easiest way to go with the swap is to get an 833 OD out of a '75+ A body or an F body, that will have the "right" tailshaft and shifter mounting location. But, if you're modifying the driveshaft anyway, you can also make a long tailshaft OD work too, and they're a lot easier to come by as they came in small trucks up to 1987. Big Block Dart has an article on what that takes...http://www.bigblockdart.com/techpages/abconv.shtml

All of the OD units are short tails.
You can see in the article above that this isn't accurate. The 833 OD's came in light trucks from 1975-1987, and those have the long tails and B/E shifter mounts. The Ebody shift mount usually isn't drilled, the trucks used the B body location. Also, the trucks have a .71 4th gear vs the .73 in the cars. There's a ton of info on the 833 OD in this article over at slantsix.org http://www.slantsix.org/articles/4-speeds/ODA833fourspeed1.htm

You'll need one of the later bell's with the 5.125" bearing retainer opening. A bell with a 4.80" opening will work if you have the input bearing retainer on the OD turned down, or you can also buy an "adaptor" input bearing retainer that has the larger 4.16" bolt pattern and a 4.80" outer diameter.

Can't help you with the hydraulic clutch, never done it.

As far as upgrading the aluminum case, I don't think its necessary for a 273 as long as you find an 833 OD that's in good condition. I know folks that have run unaltered 833 OD's behind 440's on the street without issue. The upgrade that's most commonly done is steel bushings for the countershaft. It's not that hard, there's an article on it somewhere that I can't find at the moment. Basically you just machine the case and insert some steel bushings to keep the case from wearing out at the ends of the countershaft.
 
i put a hydraulic clutch in my 41 plymouth coupe when i installed the slant six with a a-833 od trand. it has worked out real good for two years now. it wasn't a bad job, took a little fabricating, and you will need to instal a clutch pedal/master cyl combo on the firewall. can't remember now where i got the parts at this time, but they came from a vendor on ebay. the slave cylinders come in puller, or pusher configuration. i used a puller. as i said, i am real happy with the whole system, and love the slant six .
 
Thanks for all the great info!

Is this correct? "A 1963-67 flywheel must be used with a 1963-67 crank and a later flywheel must be used with a later crank. (Measure your crankshaft hub.)"
 
yes, that is correct. the crank register is larger starting in 68, and must be used with the correct flywheel with the larger hole in it.(also the correct converter must be used). you can use an early trans with the later motor by getting an available bushing for the crankshaft, and putting on a later (68 up) flywheel.
 
All of the OD units are short tails. If you can, get all of the pieces from a Volare/Aspen, and then buy stock replacement clutch parts as needed.
Hydraulic clutch? as in a slave or hyd T/O bearing? The hyd T/O bearings are very expensive.
You will need to replace the rear gear. In OD your final drive would look like a 1.9... To maintain your 2.73 final you will need a 3.9 to start.


Hydraulic clutch as in a slave
 
I'll see what I can do here.

As far as a clutch, you're probably going to want a 10.5" for the 130 tooth flywheel.

The easiest way to go with the swap is to get an 833 OD out of a '75+ A body or an F body, that will have the "right" tailshaft and shifter mounting location. But, if you're modifying the driveshaft anyway, you can also make a long tailshaft OD work too, and they're a lot easier to come by as they came in small trucks up to 1987. Big Block Dart has an article on what that takes...http://www.bigblockdart.com/techpages/abconv.shtml

You can see in the article above that this isn't accurate. The 833 OD's came in light trucks from 1975-1987, and those have the long tails and B/E shifter mounts. The Ebody shift mount usually isn't drilled, the trucks used the B body location. Also, the trucks have a .71 4th gear vs the .73 in the cars. There's a ton of info on the 833 OD in this article over at slantsix.org http://www.slantsix.org/articles/4-speeds/ODA833fourspeed1.htm

You'll need one of the later bell's with the 5.125" bearing retainer opening. A bell with a 4.80" opening will work if you have the input bearing retainer on the OD turned down, or you can also buy an "adaptor" input bearing retainer that has the larger 4.16" bolt pattern and a 4.80" outer diameter.

Can't help you with the hydraulic clutch, never done it.

As far as upgrading the aluminum case, I don't think its necessary for a 273 as long as you find an 833 OD that's in good condition. I know folks that have run unaltered 833 OD's behind 440's on the street without issue. The upgrade that's most commonly done is steel bushings for the countershaft. It's not that hard, there's an article on it somewhere that I can't find at the moment. Basically you just machine the case and insert some steel bushings to keep the case from wearing out at the ends of the countershaft.


Great info and links!

Thanks

Is this measurement correct? A 1965 273 Flywheel measures about 11 1/2" across the face of the flywheel, it's a 122 tooth.

Have you heard of this working? The 10 1/4" slant 6 van clutch assembly will fit the early 273 flywheel.
Does the pressure plate for a /6 have the same bolt pattern as the one for a v8?
 
...yeah, well, so my fingers get ahead of my brain some times...all PASS CAR O/D are short tails....the OP was referring to F bodies ...
And, if you are dealing with truck parts, then keep in mind that the 143 tooth wheel was a truck piece and had a larger bell to match. No workie with the 130 tooth wheels.
 
If you find an OD tranny you'll probably want to go through it.More than likely the bearings are shot.Brewers 4 speed has the kit.I just did this to mine.
 
1965 Abody 904 to A833 OD swap info

Flywheel

1963-67 flywheel must be used with a 1963-67 crank.

64-67 273 size 9.5 in. Part number 2463256 122 tooth ring

Clutch

A10” clutch can be used with special bolts.
The 10 1/4" slant 6 van clutch assembly will fit the early 273 flywheel.

Pedal and Fork

On the original 1964-66 A-833 cars, everything between the driver's left foot and the clutch release bearing (AKA the throw out bearing) is the exact same setup as the 1963-1966 slant six A-903 three speed cars. This includes the z-bar (torque shaft), clutch fork and push rod. On later A-bodies and other platforms, you may need to "mix and match" linkage parts. Be aware that the early bell housing used the small slant six clutch fork and the slant six z-bar needs to be used with it to get the correct movement on the release bearing. The later Overdrive bell housings used the longer V8 clutch fork.

Hydraulic Clutch

For those of you wanting to convert to a hydraulic clutch and use stock fork configuration DO NOT use a 5/8 " bore master cylinder!
There are several slave cylinders available with long travel that will do the job if you have a master cylinder that will move enough juice. The 3/4" is the absolute minimum to use and the 13/16 or 7/8 are needed on the larger bore slave units. The 84' Jeep scrambler slave has long travel and an interesting mounting flange. It has a 7/8 bore though so plan on using a large master cyl.

I am 99.9% certain now that the master cyl (13/16 bore) and slave cyl from a 1985 Jeep CJ or Scrambler (7/8 bore) will do the trick. The slave is at O'Reilly for $18.19 and the master at advance is about $57. Part #s CSA11956 and 39738 respectively.... Have to fab a bracket for the slave and get your flex line figured but no big deal. The push rod will be rather simple 3/8 bolt or all thread cut and rounded at proper length. Just figure out your pedal travel and geometry and it's a done deal.

Transmission

get an 833 OD out of a '75+ A body or an F body, that will have the "right" tail shaft and shifter mounting location.

1975 thru 1987 Overdrive 3.09:1 - 1.67:1 - 1:1 - 0.73:1 (Trucks used a 0.71:1 fourth)

A bell with a 4.80" opening will work if you have the input bearing retainer on the OD turned down, or you can also buy an "adapter" input bearing retainer that has the larger 4.16" bolt pattern and a 4.80" outer diameter.


Here are the start-off ratio calculations: (2.47 x 3.91 = 9.65 start-off ratio) and (2.47 x 3.55 = 8.77 . . .)
Note: as a general "rule of thumb" a 10 to 1 start-off ratio is pretty good for a "street - strip" Slant Six

Drive shaft




Floor Pan
 
Has anybody used a pedal like this?
 

Attachments

  • aaf-all41014.pdf
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2463411 9-1/2" clutch A-745/A-903 1964-1966 A-body 273

2463411 9-1/2" clutch A-745/A-903 1964-1966 A-body 273

2463413 9-1/2" clutch 3-spd 1964-1966 A-body 273

2465523 LA A-833 1964-1966

2465523 9-1/2" clutch A-833 1964-1966 A-body B-body 273

2465524 9-1/2" clutch A-833 1964-1966 A-body B-body 273
 
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