I just purchased an A833 OD trans (82/85 GM 1/2 ton truck/van application). I plan to install this in a 1964 Olds F-85 that will have an Olds 455 installed in it (regular gas, torque cam, 4 bbl, dual exhaust, 330hp/490ft-lbs, 5500rpm motor). The rear end will be upgraded with an 8.5" 10 bolt rear end. Any suggestions for a street gear ratio?

That really depends on the gear ratios in the trans. If they are the same as the MoPar applications it should have a 3.09 first gear and something like a .69 fourth. I'm thinking somewhere around a 3.55 rear gear would work well. My first car was a '78 Chrysler LeBaron with a slant six/833OD combo and stock 2.96 gears with something like 215/75-15 tyres and the overdrive gear was pretty worthless at any speed below 60 mph or so. It felt like the engine was idling down the road and really didn't pull at all. Probably wouldn't be a problem with a big torquey motor like your bigblock Olds.
Is that an iron or aluminum case trans?

-James

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James, the trans has an iron case. From the info I have so far: 1st 3.09, 2nd 1.67, 3rd 1.00 and 4th .71(truck). OD for cars is .73, as I understand it. Looking at the stock shift linkage, this trans came from a 1/2 GMC van. A quick calculation using a 3.55 rear gear yields an effective OD rear gear ratio of 2.52:1, which is doable for a 455 with peak stock torque of 490ft-lbs@2400rpm. BTW I appreciate 6 cylinders too; I also own a 67FB OHC 6 Sprint :>)

Thanks, MS

Hey MS
My first car was a 64 F-85 330 V8 3spd on the floor(my dad bought new) I started using it in 66 then got drafted
Memories
Frank

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

Good deal it's got the iron case. Should be a bit tougher than the aluminum box. On the gear situation I was a bit more worried about having a useful first gear as well. Those ratios you list sound about right. Guys usually point out the wide ratio being a drawback to this trans, but with a fat powerband which I'm sure you'll wind up with you should be good to go. Should be lotsa fun!

-James

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Does anybody have an A833 shift knob for sale??????????

Thanks, MS

I would love to hear more about that factory 4 bbl OHC Poncho! There may be one near here sitting in the weeds.

I always thought the 833OD was a Mopar only thing

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'72 Duster 198 stock cam, 3:23's

93 D350 Cummins THD Maxfuel 35mpg parts to hit 400hp+ Suncoast Cat2 A518, converter DDP Stage III injectors 62/64 HX35, 3 piece manifold, 4" Diamond Eye, Gear Venders OD. Stage I street/tow PDD head on order.

My 67 FB has been in the family since it was new; 1bbl OHC 6, auto, manual steering/brakes, 2.73:1 rear gear, white, red interior, dealer installed ralley wheels and space saver spare.
I have upgraded it with the factory Sprint cam and 4bbl intake/exhaust; complete with Q-jet spreadbore carb..............23mpg on regular gas. The tall gears make it a dog off the line, but it did run the entire 1/4 mile in low range before upshifting; going through the traps at 90++mph! I think it would do a faster 1/4 mile and better mpg with a 3.08:1 rear gear or maybe a Jetaway(switch pitch) trans; future plans.

As for the A833 OD, I thought the same thing--------Mopar only. Wrong! I was over at Dan's Gears(my gear man) shop one day, trying to get some ideas about OD. We talked about Riverside OD gears for a Muncie 4 speed, but finding good M21 for a decent price or the cost to rebuild one.....$$$$$.
Dan mentioned he had two A833 OD's for GM(2wd & 4wd)..............WHAT!!!! He explained that New Process had made a few of these for 82-85 GM 1/2 ton trucks & vans(RARE). The only differences are the input shaft/collar and the short shaft tail housing.

I talked Dan out of the 2wd trans and he gave me the good buddy price. He will get my business for the rebuild too.

MS

GM used a number of New Process components over the years. For many years, if not still, they used NP transfer cases in their 4x4 applications.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

I think with that light car, and that big engine, you can pull any rear gears you want. When I had the 833OD in my slant dart, with .321 gears I could cruise at 40MPH at 1500 RPM, and it felt fine. I later had the same tranny in the 360 Dart, with a 274 rear, and it would pull 40 MPH at 1200 RPM, and accelerate smoothly when asked to.

Interesting that GM used them some too. I would think a Turbo Hyromatic would be the ticket there though. The Jetaway trannys were great for heavy cars, but you would not need that super low first gear. I think they worked out close to 20:1 final ratio in low when floored. They were designed to get a 4500 lb car going in a hurry, which they would do.

Sam

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Sam, B&O made 2 versions of the Switch Pitch; TH400 and a variant of the 2 speed ST300(Jetaway). The later would work well with an OHC6 with a 2 or 3 series rear gear. The TH400 requires 50hp just to turn it. My F-85 started life, according to the build sheet, with a Switch Pitch ST300.

I think you will be real happy with the 833OD tranny. Especially since you have the cast iron case. The advantage there is that the counter shaft sits in the case, and the aluminum ones get loose and the counter shaft will vibrate. This is is pretty much not a problem with the cast iron case. Even though it weighs considerably more, (maybe 50 lbs more), I would stay away from the aluminum version.

I was not aware that the 2 speed GM trannys ever bore any other name other than Power Glide. Thanks for setting me straight. I always thought the Jetaway was used exclusively on the 4 speed version. All my big Pontiacs had a Jetaway tranny. First gear was so low that big v-8 sounded like it exploded when you floored it. It shifted out of first at somewhere around 18 MPH @ 5500RPM. The two speed variants that GM insisted in putting in their smaller cars was why I never bought an automatic SOC 6 Firebird. I ended up with my first Duster instead.

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