Hot Rods Chevy TH700-R4 transmission ID help

I "inherited" a 700R4 transmission in my 1950 Chevrolet with a 350 ci engine. The code number on the p***enger side rear, just above the pan reads: 0 (actually looks more like a backward C) YZ317C.

Here's what I've gleaned from various sources on the interwebs:
0 = 1990 model year. (This isn't really likely. I'm pretty sure the conversion to the 350 occurred before that and the crate motor casting number indicates it's from '82-'85 and the heads casting code indicates they were originally manufactured in 1974.) If 0 ain't it, what would a backwards C mean?
YZ = model type. This is what I'm really interested in. What model vehicle did it originally reside in?

317C = manufactured on the 317th day of the year during the second shift.
I haven't dis***embled anything so far other than removing valve covers. I haven't dropped either the engine or transmission oil pans and I haven't researched how many output splines the ****** has. At this point, if it ain't broke, don't fix it. I'm trying to learn as much as I can so that when it does break I can fix it. You all know the drill of heading to the parts store. If they don't have "that guy" who knows what he's doing the conversation always starts with "what year and model" and goes downhill from there. (My "guy" retired last month!!)

Any help would be appreciated.
Lenny

 

The main thing I can tell you is that it is imperative that the TV cable is adjusted correctly! If not, you will be getting the opportunity to drop the pan and or completely take it apart very soon. As it will smoke, the direct clutches completely out of it.

 

If “0” is for the year, it can’t be 1980. It can’t be 2000 either.
Somewhere around 1987, GM upgraded them, maybe someone can give you details.

Does it work properly ?

 

Only having two model letters means it is an '82-'85 transmission. 1986 onwards have three letters in the code for the model.
The only numbers used at the start that could resemble a "backwards C" would be a 9 from 1982 or maybe a 3 from 1983.
I would guess it is one of the early transmissions.

 

You guys have been extremely helpful.

Kevin, I have not checked the TV cable since I bought the car, but have driven it a couple of thousand miles and it's been shifting normally. I now have another task to follow through on!

Budget and Twenty8, upon closer inspection, where the date number should be there's a 3/4 circle facing like a backwards C. This is still a mystery but I'm not going to fret over it.

Twenty8 and Joe Blow, you've provided the best information for what I was looking for. With only the two letter code YZ leading to part number 61650, the transmission was originally in an '82-'85 Camaro, Firebird, Caprice or full sized pickup. The engine, even though it is a crate engine, appears to have originally come from a 1980 C-10 pickup.

Sooooo, next time I head to the parts store I'll tell 'em I have a 1980 C-10 pickup even though it looks just like a 1950 two door Bel Air coupe.

Because you guys were so helpful I have some useless trivia for you- 1950 was the first year for the Bel Air, even though there's no mention of Bel Air badging anywhere on the car. It was called a "poor man's convertible". Instead of an operable convertible top, the fixed roof was welded on.)

Lenny

 

^^^^^ 2 door hard top’s only thru 52 were Bel Air’s.

 

You are correct Johnny Gee. The new body style in '53 led to the Bel Air becoming a sedan.

 

^^^^^ Trim became the deciding factor, not the roof any longer.

 

One thing you should be aware of is that the early model trans had a different spline count on the input and therefor used a different converter. They don't interchange. The later model versions had some good upgrades and eventually became the 4L60 for a few years (early 90s) then later became the 4L60E which needed a computer.

 

Might want to get this book from Amazon

 

Good info, thanks everyone! Especially @zipmann for starting the thread.

I have a freshly rebuilt (?) 700R4 that’s been on the shelf for years.
Anything needed before it’s put into service? Thinking about putting it in my 41 pickup with the 330 Desoto, just need to change out the 3.25 rear gear.
Any recommendation on that?

 

I'd leave the 3:25 in it and see how it drives.............you can always change it later. You might want to put some fluid in the converter and maybe put some in the trans and roll it over and let it set at a couple of angles so all the internal parts get a fresh coat of fluid, rub a little on the front seal ............

 

Thanks, will do!