Technical How to convert a manual to automatic’63 Impala

I had forgotten about the shifter bolting to the floor pan. They were a bit notch shifting best I remember. Not so sure about the mounting holes not being drilled though, the one I took out they were drilled and tapped, this came out of a 20,000 mile wrecked car. I remember I didn’t care for the shifter, so I bought a used Hurst Indy shifter I think it was, bolted right up . Doubt they even make those shifters anymore, they were a bit cheaper than a comp plus was. Just had to put stop bolts in the case, the holes were there just no bolts with it.

 

Must have made 'em both ways. But over the years I've seen a couple of them not drilled and tapped for shifter mounting.

 

My budget is $3K

 

Do you have tools and equipment to do the job?

 

I’ve got 2 jacks ,4 stands, tranny Jack, all the hand tools, compressor,wood blocks, if I don’t have a certain tool. I will buy it. I can do almost anything as long there are instructions and easy math. The gear ratio thing is like speaking Russian to me.

 

I called a tranny shop and they recommend putting a 700R4 with overdrive tranny. They quoted $4500 to do it. Atleast 1/2 of that price will be labor. There’s a 2 month wait so I can thinking about diving into this project myself.

 

Установка 700R4 довольно проста. Вам понадобится гибкая пластина. Лично я бы выбрал 4-скоростную. Передаточное число должно подходить для 700R4, поскольку это автоматическая повышающая передача.

 

Totally Cyrillic, dude!

 

The 700R4 is great for cruising but if you're not familiar with how to set up the TV cable, I would recommend you leave that to a shop that is qualified. In all honesty, the quote of $4500 to do the swap to a 700R4 is not offensive at all, especially if that's including them supplying the transmission and associated parts. The transmissions alone now go for over $2000, plus you'd need all of the associated parts like the crossmember and mount, shifter, torque converter, flexplate, cooling lines, trans cooler, TV cable, TV bracket and carburetor geometry correctors.... it adds up quick. At $4500, I'd say you're in less than $2000 in labor, which is likely about 20 hours. As I said previously, if the TV cable is not properly adjusted, the 700R4 will destroy the 3-4 clutch pack virtually instantaneously. I speak from personal experience in that regard.

A TH350 is the easiest route but you lose the OD and you'll have the same final gearing as you do now. Third in your manual is 1:1, third in the TH350 is 1:1. No different. All you need to do is get the flex plate, converter and trans, and hook a vacuum line to the modulator and you're basically done. You can, but don't need to run it with the kick down linkage.

 

Maybe a good reason to consider a TH350-C with the locking torque converter. The relative ease of installation of the TH350 with a drop in engine RPMs at higher speeds when the converter locks up.

 

You raise a good point. Technically, because the TH350 is not a lockup transmission, RPM will be slightly higher than the manual with the same final drive ratio, since there is some slipping through the converter. The TH350-C with a lockup converter, basically brings it in line with the manual, since the manual is "locked" when in gear. So there's no drop in RPM over the manual, it's a lateral move with the lockup TH350-C, and cruising RPM will be a bit higher without the lockup converter.

 

Also, through this whole thread, I don't see where the engine the car has was identified? I think the analysis would change if we're talking about a 6 cylinder, 283, 327, 409, or something else that wasn't germane to the car.

Also, do we know the rear axle ratio? Because if it's a 3.08, I can tell you from experience that a 700R4 is not going to like that tall rear axle ratio, and would be much happier with a 3.50 or above. On the contrary, if it's a 3.08, the car will be very happy with a regular old TH350 and the car will be just fine without OD.

 

Back on the first page the OP mentioned it being a 327, but nothing more about which version.

 

It’s a 8 cyl 327. 63 impala 3 on tree

 

We have a 63 327 ss impala with a powerglide in the family. My grandparents bought it new in 63. I haven’t driven it in years but as I recall it was a creampuff on the highway. The engine turned console with the gate looking shifter is a thing of beauty. The car is pristine white with turquoise leather interior, can’t hardly take it out without someone trying to buy it. Wish I had some pictures to share.

 

Yep, it's bolt in expect for the front drive shaft section needs to be shortened. My car went from the old (62-earlier) cast iron powerglide to a TH350 and it was a great swap.

I disagree. These were primarily 3.36 or 3.08 rear gear ratio. At most you're talking 250 rpm difference between the two. Nothing you'll notice for a cruiser. My 62 has the 3.36 with a TH350, and I've taken it on a lot of road trips cruising at 75 MPH. Works great.

The labour is mostly the same if you go Powerglide, TH350, or 700R4. What changes is the lockup convertor (700R4), shift linkage, TV cable (700R4), driveshaft length, etc.

Your car should have a 3.36 rear gear. If most of your cruising is at 65 MPH or less, the overdrive will be pointless. If you want to cruise at 75-80+, you'll notice a drop in RPM but the SBC can take the higher RPM with ease.

The TH350 fits better and makes a nice cruiser. I take mine on lots of road trips and it works great.

Don't let others scare you into needing overdrive or you should leave it a manual, etc. How you drive the car and what types of roads and speeds can help the decision.

He said it is a 327, and a 327 with a 3-speed has a 3.36 rear gear. The 3.36 is perfectly happy with a TH350 from personal experience.

 

So I mostly drive on the street at normal speed and 12mi , 2 days a week @65mph. I’m not a racer. Just want a reliable Sunday driver.
So TH350 will be my best option. Should I find one at junkyard or buy it new? The shortening the driveshaft part is out of my experience . I can take it to driveshaft pros but how do I know what length it’s supposed to be?

 

T-350 getting scarcer in junkyards. You may be able find one that somebody switched out for an OD trans or as part of an LS swap. Of course used ones are a
crap shoot as to how good they are or how truthful the seller is.

Driveshaft guys will tell you how to measure; but you will probably have to take the front shaft off and put the rear shaft and hanger bearing back in to do so. If I remember right it is supposed to to be the same length as an original 4 spd shaft?

 

You'll need a TH350 driveshaft yoke because the spline is different to the old SM318
once the trans is mounted in place, install the yoke all the way in, then slide it out 1" AND support the rear axle with jack stands under the axle tubes.
Then bolt the old D/shaft in but leave it hanging down. [this also applies to the front D/shaft of 2 piece types]

Measure the distance from the centre of the cross in the yoke to the centre of the cross in the rear universal. [or the hanger universal on 2 piece]
This is the measurement that the Driveshaft shop will need

 

Thanks for the great illustration. Is there any thing else that needs fabrication? I saw someone mention flex plate and cross member moving back. Can I use what I have?

 

I found this locally. Will this work? Looks like it needs to be rebuilt. If the info is out there I can rebuild it?

 

Thats a 4 wheel drive trans, not what you need.

 

Pm me I will give you info on a local builder . I may have a core.

 

Before we all jump to conclusions you need to crawl under you Impala with a tape measure
Engine to transmission length, and Engine to rear mount bolts

 

Not sure, but you may have to remove the old input shaft bearing in the rear of the crankshaft. A test fit of the flexi and torque converter will let you see if the snout clears the bearing or not..

 

Personally I would drive the tires off that 327-3 speed Chevy.
I would rock in that ‘63 Chevy column shift!

I think it’s really a lateral or even a backwards move to go automatic.

1st....double clutch or stop
Sloppy shifting? Bushings, linkage, renew column, adjust. Then bang on it like a toy drum

More pep? Pepper /soup up the engine some.
More quick? Consider a lower rear gear.

 

I'd first install a Hurst floor shift with the original three speed. The old Syncro-Locs were good shifters, as are the newer Mastershift shifters. Just doing this will make the original tree speed trans shift much better. The Mastershift shifters are currently on sale and in stock at Summit.

Hurst Mastershift 3-Speed Shifters 1963 CHEVROLET IMPALA Parts & Accessories | Summit Racing

However, this is for just the shifter. An installation kit will also be needed. This is the Hurst part number for the installation kit that I bought about 15 years ago, for my 1960 Chevy Impala with the stock three speed.
Hurst # 367 3111

 

Yep
A white knob Hurst just drips Hamb period upgrade.
A much better choice than a slush box!

I’ll be honest, the guy is looking at 4x4 transmissions.
He says he does not understand gear ratios..... this understanding is needed for a transmission swap.

I think he needs to stick to simpler stuff like shifters and learning what he has instead of getting deep into a transmission swap. At least for now until 727 gets some more experience and learns.

 

Yeah if you guys saw my older posts a few months ago. I just removed my tranny and it was a bitch to get back in. I learned to never again work on a sloped driveway with pavers by myself. I haven’t decided if I’m going to do it. My engine has been burning oil so that might dig into the tranny conversion project.

 

A fresh big block (W or Mystery Motor) is a sure cure for a tired smoky 327.

Caution.......
Small Block vs Big Block is like beer vs whiskey.
With a small block ; kind of like beer, you know where you are at. A small block will let you know. You can feel the “top” with a small block. It will quit pulling then the valves may rattle.

A big block, like whiskey can get get you in trouble before you know it. That joker will pull until something breaks.