1970 buick gs 455 3 speed

was it a ford tranny?

 

In the parts books GM discretely refers to the Ford 3 speed as the "Dearborn" 3 speed. :laugh:

 

My 68 GS 3 speed had the Ford Toploader, in researching these when I had the car my understanding was that they were available in GM A body cars Pontiac, Olds and Buick, not Chevrolet, 1967 through 1969 model years.

I spoke to the original owner and inquired why he ordered a 3 speed and this was his story.

He was in Vietnam and wanted a new 68 GS 4 speed Convertible when he was discharged from the service. He had his brother go to the local Buick dealer in IL and order the car for him, specifically asked for the manual console "Consolette" with tach and the other options, colors etc. When the car came in it was a 3 speed and the dealers response was that they mistakenly did not check the 4 speed specific box on the order form, however as he did check the manual console option the factory defaulted to the 3 speed transmission.

I assume that if he had not checked off the consolette option, he may have ended up with a 3 on the tree.

 

GM started using the Ford 3 speed in Pontiac in 64, and in Buick in 65. I believe Pontiac continued thru 71 on some models and Buick thru 69.

 

Im no expert but this is what i think/believe as best as i can remember..getting old sucks

69 was the last year for the dearborn 3 speed in a GM intermediate..GM absolutely hated paying an outside vendor..like Ford...its #1 competitor...and developed a GM vendor supplied trans..heck..in 64 Pontiac wouldnt allow the HURST logo on their HURST shifters in a GTO....and even with that, it was 66 before GM outsource real HURST rods for said shifters...GM supplied the rods until then..and they where junk..

in 70-73=4ish, the 3 speed in floor shift cars was the "Super Muncie" 3 speed, it was upgraded, and nearly bullet proof, and just about as tuff as the dearborn top loader...( i dont know if the "SUPER" was GMs lingo or street, but that three speed has been called a super muncie around here since i was a kid)

column shift got a saginaw 3 speed and they where fragile...hence the choice of low hp cars..

theres a reason why the default trans in a muscle car, like a GTO or 442 or GS etc was A FLOOR SHIFTED 3 SPEED..all about being able to warranty the transmission, ya cant sell a Stage 1 car and it grenades the trans the first clutch dump

my 3 speed 71 GTO would out run about every 4 speed of the same era...the gear split was better for the HP and torque range...and i absolutely believe the 70 Stage 1 3 speed beat the 4 speed..i didnt just read it, i lived it...

 

3 on the tree was not available in the GS400.

 

are the Dearborn toploaders interchangeable dimensionally with the Muncie Super 3 speeds? and the Saginaw 3 speeds. If one doesnt work can you just drop the other one in place without cutting driveshafts or tunnel sheetmetal, linkages etc.?

 

they do swap with no mods to the tunnel, but there are diffs..like shifter mount, shifter rods etc..minor stuff that can be handled with no serious issue..and they all look different from each other so easy to ID...and from 65 to the 80s the GM bell housing it drilled and tapped for both the GM trans and the top loader/dearborn..they can use the same clutch plate and yoke too...i just cant remember the drive shaft stuff, but i believe they are all the same length and the trans mount is in the same place too

i cant remember the weights right now but the muncie and top loader are very heavy..the sag is lighter, but not by much, and it wont take a lot of abuse..

 

Having owned a 64 Impala SS 409 4bbl 4 spd with the saginaw I can relate This trans was like tissue paper when speed shifting. being in my teens I had no idea I could switch to a different trans so after the 3 rd one I sold the car. No junk yards had any left my boss helped me rebuild mine from the parts I had left from the 3 and his own stash and it went down the road and started me on a different path which I only dabbled in for 1 car a 69 RR 440 4spd. Also a bad deal with a twisted unibody. No wonder it jumped sideways with every gear change. :spank:

 

Maybe I'm showing my age but I've always enjoyed a three speed. If a car had a four speed that's fine too (I wouldn't change it). Both of mine are autos right now but I hope to have another manual one day. Take what you have for a drive and enjoy it.
Robert

 

A GS 400 default was the floor shift- ----the 3 on the tree would have been the default for the GS350 (obviously no convertible available ) No sweat

 

The hurst-shifted toploader 3-speed in my 68 GS 350 was the best shifting old school manual trans I have ever experienced. Like butter. The trans, shifter, bellhousing, flywheel, carb, and a few emblems are all I have left from that car. I highly doubt a 455 car would show much difference in the ET compared to a 4-speed. If I were on a budget and had to choose between a 455-3-speed or a 350 4-speed it would have been a no-brainer. Or choosing between a standard 455 4-speed or Stage 1 3-speed. I am sure some people's budgets were that tight. And it would be all set up for a scrounged 4-speed swap later if wanted.