1968 3 Speed
Thread Starter
Navigator
Joined: May 2016
Posts: 9
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1968 3 Speed
I recently picked up a 68 with a saginaw 3 speeed - I know.....not many around. considering changing it to a 4 speed. Is it as simple as swapping the transmission and shifter? or is there more involved.
Also interested to hear opinions as to whether I SHOULD do it. I understand it's rare. Rare is good when you're talking about an L88. This is a 327/300hp. The 3 speed is rare because people wanted 4 speeds.
thanks!
Also interested to hear opinions as to whether I SHOULD do it. I understand it's rare. Rare is good when you're talking about an L88. This is a 327/300hp. The 3 speed is rare because people wanted 4 speeds.
thanks!
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
You need to find an early Muncie with the 10 spline input shaft and shifter and it's a direct swap.
If you use a later Muncie or BW ST10 with the 26 spline input then you will need a new/correct clutch disk and driveshaft yolk.
As for the "SHOULD"... it's your car and you can do with it what you want. Besides swapping a 3spd to a 4spd is not a big deal. It's an easily reversible modification as long as you keep the original 3spd transmission and shifter assembly under your work bench.... Look how many of us are swapping in 5 and 6 spd transmissions today to make our cars better drivers.
Will
If you use a later Muncie or BW ST10 with the 26 spline input then you will need a new/correct clutch disk and driveshaft yolk.
As for the "SHOULD"... it's your car and you can do with it what you want. Besides swapping a 3spd to a 4spd is not a big deal. It's an easily reversible modification as long as you keep the original 3spd transmission and shifter assembly under your work bench.... Look how many of us are swapping in 5 and 6 spd transmissions today to make our cars better drivers.
Will
Drifting
Joined: Apr 2011
Posts: 1,689
Likes: 174
From: Deerfield Illinois
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VERY rare! I believe the made about three hundred of those before they discontinued the option. I can understand your dilemma, because I have a three speed auto and it could use another gear. I'm curious as to what rear gear ratio you have.
Like already stated throw in a 4-5-6 speed and nicely crate up the 3 speed and enjoy the ride.
Like already stated throw in a 4-5-6 speed and nicely crate up the 3 speed and enjoy the ride.
Le Mans Master
Joined: Aug 2010
Posts: 8,507
Likes: 501
From: Bussey, IA
How does it run with three? Is it decent response?, are the rpms in an acceptable range?, does it get decent fuel mileage? What are you looking for performance/ driving wise? As stated, if you choose to change it out, keep it for resale as it is obviously a VERY rare option. Do what makes it fun to drive and enjoy it!
Thread Starter
Navigator
Joined: May 2016
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I'll definitely keep everything. Not sure how it runs with the 3 speed. I got it with the engine and transmission out of the car. I've driven other 3 speeds (not vettes) and it's felt like something was missing. So, i figured if I'm going to do it, now is the time.
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
I agree with this. Having the OD is really nice if you really want to drive the car. We drive ours on all day 200-400 mile adventures. If you're just going to cruise-ins and shows and putting low miles on it then 3 or 4 spd would be fine. If you are worried about original leave the 3 spd. In any case keep it.
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Team Owner
Joined: Jun 2000
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From: Southbound
Cruise-In II Veteran
To be honest, the 3 speed is rare because most people wanted anything other than the 3spd. 
I haven't done the math in a while, but that's probably in the neighborhood. For 68 and 69, the 3 speed manual was the base transmission. You got the 3 speed unless you ordered something different. All other trannies were optional at extra cost. Most people opted for a four speed or the TH400.
The wide ratio four speed became the base transmission beginning with the 1970 model year.
The wide ratio four speed became the base transmission beginning with the 1970 model year.
Last edited by Easy Mike; May 30, 2016 at 09:07 AM.
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
BUT, with the trans already out of the car, as long as you are keeping it, put in whatever the heck you want! 4 spd, 5 spd, overdrive, CVT... go for it!
(I had 3 on the floor in my first car.... it was a 74 AMC Gremlin X!!! ...yep, sure felt like something was missing... an engine!
)
Last edited by PRNDL; May 30, 2016 at 07:38 PM.
Burning Brakes
Joined: Apr 2008
Posts: 1,222
Likes: 93
From: shelbyville West Michigan
M20 4-Speed Manual Transmission 10,760
M21 4-Speed Man Trans, close ratio 12,337
M22 4-Speed Man Trans, close ratio, hd 80
M40 Turbo Hydra-Matic Automatic Trans 5,063
I know splitting hairs....
but I would ditch it, put in a 5spd. if you're going to do anything may as well do it all the way. of course keep the old parts in case a future owner wants to return it to stock, but as stated on here many times before, "Rare doesn't mean desirable!"
Drifting
Joined: Jan 2012
Posts: 1,908
Likes: 129
From: Fredericksburg Virginia
What if they offered a 2 speed automatic? And there were only 4 individuals that purchased said 'option'?
I have 1 of 4 ever produced!!! Awesome!!! Well...ya...it actually drives like a pig. I hate it. But it sure is rare!
The only 3 speed I ever drove was a column shift. Remember those? They weren't too fast, either.
I have to say, though...that shift pattern is a great example of elegant simplicity.
I'm with others. If making ANY switch, I'd go straight to a 5 speed. Wouldn't even think about it.
Burning Brakes
Joined: Jun 2011
Posts: 816
Likes: 11
From: lewisburg wv
honestly I didn't even know a 3spd was offered (except auto), but subtracting optional transmissions from total production I get 326 that must be the 3spd.
M20 4-Speed Manual Transmission 10,760
M21 4-Speed Man Trans, close ratio 12,337
M22 4-Speed Man Trans, close ratio, hd 80
M40 Turbo Hydra-Matic Automatic Trans 5,063
I know splitting hairs....
but I would ditch it, put in a 5spd. if you're going to do anything may as well do it all the way. of course keep the old parts in case a future owner wants to return it to stock, but as stated on here many times before, "Rare doesn't mean desirable!"
M20 4-Speed Manual Transmission 10,760
M21 4-Speed Man Trans, close ratio 12,337
M22 4-Speed Man Trans, close ratio, hd 80
M40 Turbo Hydra-Matic Automatic Trans 5,063
I know splitting hairs....
but I would ditch it, put in a 5spd. if you're going to do anything may as well do it all the way. of course keep the old parts in case a future owner wants to return it to stock, but as stated on here many times before, "Rare doesn't mean desirable!"
Race Director
Joined: Oct 2008
Posts: 19,130
Likes: 1,667
From: Long Island
I would go with a 5 speed conversion - no cutting, and put the 3 speed into a bag and box for the future.
I did the 4 sp to 5 sp conversion on my 71 and it's the best thing if you want to drive the car. A/C is another great thing - next year.
If it's a show queen / NCRS keep the 3 speed.
I did the 4 sp to 5 sp conversion on my 71 and it's the best thing if you want to drive the car. A/C is another great thing - next year.
If it's a show queen / NCRS keep the 3 speed.