Slip yolk
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Instructor
Joined: Apr 2021
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Slip yolk
1) I’m converting from a th400 to a 1964 Muncie 4 speed in my 1973 corvette, the th400 slip yolk doesn’t fit so am I supposed to buy a 1964 Muncie slip yolk or buy one that says it fits a 1973 Muncie because my cars a 1973?
2) will I be able to keep this same drive shaft that I used with my th400 or will I need to buy a diffrent driveshaft?
2) will I be able to keep this same drive shaft that I used with my th400 or will I need to buy a diffrent driveshaft?
Tech Contributor
Joined: Aug 1999
Posts: 15,154
Likes: 3,959
From: Connecticut, USA
First, I would check the 64 Muncie to make sure it's still good. That was the first full year of use in vettes and they had some issues with the smaller cluster cross shaft and brass blockers.
The 64 rear spline is not the same as the TH400 as you found out. The Muncie used 27 spline output and the TH400/Super T10 had 32 splines so yes you need to find a 64-70? slip yoke, the later Muncie's I believed changed to 32 output and fine input. If you find a used one make sure the OD is smooth, no pitting or grooves or you will have a leak.
The 64 rear spline is not the same as the TH400 as you found out. The Muncie used 27 spline output and the TH400/Super T10 had 32 splines so yes you need to find a 64-70? slip yoke, the later Muncie's I believed changed to 32 output and fine input. If you find a used one make sure the OD is smooth, no pitting or grooves or you will have a leak.
Thread Starter
Instructor
Joined: Apr 2021
Posts: 133
Likes: 5
First, I would check the 64 Muncie to make sure it's still good. That was the first full year of use in vettes and they had some issues with the smaller cluster cross shaft and brass blockers.
The 64 rear spline is not the same as the TH400 as you found out. The Muncie used 27 spline output and the TH400/Super T10 had 32 splines so yes you need to find a 64-70? slip yoke, the later Muncie's I believed changed to 32 output and fine input. If you find a used one make sure the OD is smooth, no pitting or grooves or you will have a leak.
The 64 rear spline is not the same as the TH400 as you found out. The Muncie used 27 spline output and the TH400/Super T10 had 32 splines so yes you need to find a 64-70? slip yoke, the later Muncie's I believed changed to 32 output and fine input. If you find a used one make sure the OD is smooth, no pitting or grooves or you will have a leak.
Tech Contributor
Joined: Aug 1999
Posts: 15,154
Likes: 3,959
From: Connecticut, USA
The Muncie will handle the 450hp as long as you don't launch the car or otherwise beat it up. The M20 & 308 was an option but a little sluggish off the line. 336 was the std ratio but the M20 will work with any ratio.
Le Mans Master
Joined: Jan 2001
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Likes: 1,372
1973bluevettee
Here you go. Double check me but pretty sure this will work:
Conversion/Adapter U-joint Spicer 5-134x or TRW 20056 (Part number on receipt is PRJ-20056)
https://www.corvetteforum.com/forums...post1601594797
Here you go. Double check me but pretty sure this will work:
Conversion/Adapter U-joint Spicer 5-134x or TRW 20056 (Part number on receipt is PRJ-20056)
https://www.corvetteforum.com/forums...post1601594797
Tech Contributor
Joined: Aug 1999
Posts: 15,154
Likes: 3,959
From: Connecticut, USA
Good point the Manual cars usually used a 1310 u-joint. The Th400 & ST10 used 1330. The Automatics, BB, Base eng with ac used 1330. There is also a different length in the driveshafts between manual and automatic.
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Thread Starter
Instructor
Joined: Apr 2021
Posts: 133
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I bought this and then I’m just going to get a new driveshaft that fits with manual trans
Le Mans Master
Joined: Jan 2001
Posts: 6,713
Likes: 1,372
1973bluevettee
The driveshaft you have should work (I suspect). I used the same driveshaft with a Richmond 6-speed and turbo 400 yoke and that conversion u-joint...... I'm not going back to the old u-joint to hook up a 200-4r with the same driveshaft.
It'll be easy enough to check once you get the yoke and the conversion u-joint.
The driveshaft you have should work (I suspect). I used the same driveshaft with a Richmond 6-speed and turbo 400 yoke and that conversion u-joint...... I'm not going back to the old u-joint to hook up a 200-4r with the same driveshaft.
It'll be easy enough to check once you get the yoke and the conversion u-joint.