'63 Buick LeSabre transmission swap questions

Imo Apita

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Joined
Feb 28, 2009
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The irony if the situation; I pushed my '79 'vette to the side for blowing the transmission and now my new project has a bad transmission also.
In any case:
The dynaflow two speed is toast on my recently bought '63 Lesabre.
I have the following options:
Rebuild it if no hard parts are damaged
Replace with a TH400 from a Jeep Wagoneer which is a bolt on.
Replace with a 700R4 which requires a $800 conversion kit.

I'm torn between the 400 and the 700R4.
With a gear ratio calculator figured out that at 80mph the engine rpm is 2300 with the 700r4 and 3200 with the TH400.
Question is it worth the extra $1000-$1200 for the modifications such as TV cable bracket and so on.

The 700r4 has a 3.06 first gear vs a 2.48 for the TH400.
I understand the torque multiplication thing but considering the Buick is about the same weight as a Cadillac (4200 ish) how much difference would a 700r4 really make compared to a TH 400?
I would like a high way gear for sure but not really convinced its worth the extra expense.
How much faster does a 4000 lbs car really accelerate with a 3.06 first gear.
The rear gear ratio is 3.23 for the Buick by the way.

Any help appreciated as I need to pull the trigger pretty soon on this one.
 
Welcome back dude.
If you're askin' I'd say it's a sign.
You have to go back on the Vette :hissyfit::stirpot:
 
IMO, more info needed....

I had a 4100 lbs Pontiac Lemans sport convertible, with a YH code '70 B body Pontiac 455 in it, with DPFI on it, that I did in my garage some 20 years ago...a junkyard adaptation off a old Caddy 425--similar to the Seville package out of the later 70's.....

and I had a 321 12 bolt Chevelle rear and a 400 auto, it was my tow car for the boat, so I had a 26 gallon Caddy tank on it, instead of the 18 gallon Goat tank ....

so I need know what you want the car to do .....towing, do the 400, cruising around without much load and you want economy, AND intend on keeping the car for a LONG time....do the 700, but most guys seem to think that 700 has a too steep first gear for any normal car, and I tend to agree, it's a good thing in the 8000 GVW Motor Home I have, and can cruise 60 at 2k rpm all day,

so need more information on uses....just as a SWAG, I would say do the 400 and live with it.....what size engine you have in the car?? OH, edit....what size Buick is a LeSabre?? B body or A body, excuse my memory....I assume you have a Buick engine...

:friends::crutches:
 
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Nice car, My dad had one when I was a kid and then a 69 that had the TH400. I drove that 69 for 3 years and it was great.
Gene the LeSabre was the full size
 
Thanks for all the kindness y'all.
It's a full size 4200 lbs with a 410 Nailhead motor which is stock for now.
Plans ? Same as what I wanted to do with the Corvette......scare women and children.
Satin black with black tinted windows.
For now keep the nailhead stock but not for long, depending on how much I need to sink into this transmission.
The purpose ?
Something like this:
A cop magnet
A Miami South beach cruiser
No need to be scared in the bad neighbor hoods since they all figure it's bad ju-ju to mess with this cracker jack
Park it and chat at the local cruise in
Spank some pimple face in the noisy import
Burn rubber at will
Cruise with the wifey,listening to tunes
Beach patrol
Scare people at the light,:clap:

You know all the usual.
Sell it make money and buy something truly evil.
Ultimate goal is to buy/create/build a cross between the "Death Proof" car and Mad Max interceptor.
Ultimate goal is a full 12 point cage 500+HP Armageddon bug-out car.
1969-1970 Charger, Dodge, Mach 1 clone kind a thing.
But now you've seen deep into my soul......:nuts:
 
So the LeSabre was a full size, equivalent to the Bonneville or the Grandville....in '73 that Grandville convertible I had was about 5500 lbs, as my '70 Lemans was weighed in at 4100 lbs empty, several times....

I have to assume your Buick being B body....from what you say....

and so to flip it....turbo 400 and not worry a bit.....:bounce:
 
Thanks for all the kindness y'all.
It's a full size 4200 lbs with a 410 Nailhead motor which is stock for now.
Plans ? Same as what I wanted to do with the Corvette......scare women and children.
Satin black with black tinted windows.
For now keep the nailhead stock but not for long, depending on how much I need to sink into this transmission.
The purpose ?
Something like this:
A cop magnet
A Miami South beach cruiser
No need to be scared in the bad neighbor hoods since they all figure it's bad ju-ju to mess with this cracker jack
Park it and chat at the local cruise in
Spank some pimple face in the noisy import
Burn rubber at will
Cruise with the wifey,listening to tunes
Beach patrol
Scare people at the light,:clap:

You know all the usual.
Sell it make money and buy something truly evil.
Ultimate goal is to buy/create/build a cross between the "Death Proof" car and Mad Max interceptor.
Ultimate goal is a full 12 point cage 500+HP Armageddon bug-out car.
1969-1970 Charger, Dodge, Mach 1 clone kind a thing.
But now you've seen deep into my soul......:nuts:

Go to V8Buick.com and post your question there. A really nice crowd. I am there for my '71 Skylark Convertible. I am sure that you will be well received and get the information you need in short time.

Pics man! We need some Pics!
 
Well I have found an ad of the car for sale from about 5 years ago.
Paint is now dull, may shine up with a buffer and has some patina here and there

63buick43474-2.jpg


63buick43474-1.jpg


Shaved door handles, poppers need to be replaced.
Very nice interior , needs a radio and speakers and maybe a Vintage Air AC
 
I would do the 700R. Use an 89 model year unit.

If Gene has his way, he will say 400, but that requires a hydroboost.:hissyfit:
 
That is a B body Buick pix above.....I really don't remember if I ever measured my Grandville, but that car was SO massive...but it also was a '73, and they did grow in size by model year '70 also.....the earlier B body cars maybe not quite 5500 lbs, but I am curious as to what is really does weigh....I suspect 5000 lbs, because of it's length if nothing else....

and the use of a HB is not really necessary, even with the disc brake and Global West front end on my '70 Lemans, the brakes were fine...never an issue...the old Grandville had decent brakes, even...dunno HOW, just did....

I would look into maybe doing a disc brake front end conversion outta a junkyard, methinks it can be bolted on....

makes me think of the old Kelsey Hayes Pontiac 8 bolt aluminum brake drums, been a while....

:smash::harhar:
 
Well I have found an ad of the car for sale from about 5 years ago.
Paint is now dull, may shine up with a buffer and has some patina here and there

63buick43474-2.jpg


63buick43474-1.jpg


Shaved door handles, poppers need to be replaced.
Very nice interior , needs a radio and speakers and maybe a Vintage Air AC

Very nice, straight body, someone did some custom body work. I like the frenched antenna too. I agree with the sinister black, two pipes, tail dragger menace theme, it would be very cool.

Gene, I don't know if there was a disc brake system available for the 63's. I think that came about 5 years later. I did the (factory) disc brake conversion on my '71 Skylark.
 
Well I have found an ad of the car for sale from about 5 years ago.
Paint is now dull, may shine up with a buffer and has some patina here and there

63buick43474-2.jpg


63buick43474-1.jpg


Shaved door handles, poppers need to be replaced.
Very nice interior , needs a radio and speakers and maybe a Vintage Air AC

Very nice, straight body, someone did some custom body work. I like the frenched antenna too. I agree with the sinister black, two pipes, tail dragger menace theme, it would be very cool.

Gene, I don't know if there was a disc brake system available for the 63's. I think that came about 5 years later. I did the (factory) disc brake conversion on my '71 Skylark.

I going on memory now....been 24? years ago....my '70 Lemans convertible was 4 wheel drum, but there was this new outfit putting out disc brake and suspension mods at the time....and so talking to the owner of Global West Suspension on the phone, he told me what to do, and it involved a '80? full size Caddy front spindle and rotors, I think, a ton of mods long forgotten, but nothing welded, all bolt on shit...I think I dropped the front end a inch or two....and the disc brakes and something in the suspension....made the car handle GREAT and stop on a dime with change in return....I switched to a later Camaro box for quicker steering....

I dunno if the engineering package changed on the A body cars from my Mom's 63 Olds F 85 to the '70 Lemans....but I know the rear diffy was changed from some oddball setup to something similar to a Chevelle....

:amazed:
 
I'm 99-44/100% sure that old nailhead uses the BOP case trans. To fit a 700-R4, you'll need to find a BOP case and I'm not sure they ever made one with that case. The 200-4R is available with the correct case. Just food for thought.

:club:
 
I'm 99-44/100% sure that old nailhead uses the BOP case trans. To fit a 700-R4, you'll need to find a BOP case and I'm not sure they ever made one with that case. The 200-4R is available with the correct case. Just food for thought.

:club:

I think you right, Tim....

:drink:
 
We pulled the trigger and are going with a 700r4 built by a local shop so we'll have somebody to talk to if things go up in smoke...:lol:
Will be about another week before things are completed.
 
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