Automatic Trans Conversion for 1962 C1
Thread Starter
3rd Gear
Joined: Jan 2009
Posts: 3
Likes: 0
Automatic Trans Conversion for 1962 C1
I did a search on this and didn't find much, if I missed something please post a link.
I am interested in fitting a higher performance automatic than the Powerglide to a 1962 C1. I would ideally like to use a THM400, but I have read that it won't fit. Is that true and what would have to be done to make it fit? Would a THM350 fit without mods? (Engine is a carbureted 400CI smallblock, so I need to be able to handle a fair amount of torque.)
I have seen kits for the GM 4L60E for a C1, but the gear spreads are extreme with that trans. (6,000 RPM first gear shift drops you to 3,200 RPM) so I would like to stay with something with closer ratio gearing. (4L60E is a 3.06:1 first - THM400 is a 2.48:1 first gear) Overdrive is not that important for my purposes so 3 or 4 speeds are both workable.
Has anyone done something like this? Or does anyone have any suggestions on things that might work?
PS. To save questions about why I don't stay with the 4-speed manual, I had an injury to my left leg that makes working the clutch difficult.
Thanks
I am interested in fitting a higher performance automatic than the Powerglide to a 1962 C1. I would ideally like to use a THM400, but I have read that it won't fit. Is that true and what would have to be done to make it fit? Would a THM350 fit without mods? (Engine is a carbureted 400CI smallblock, so I need to be able to handle a fair amount of torque.)
I have seen kits for the GM 4L60E for a C1, but the gear spreads are extreme with that trans. (6,000 RPM first gear shift drops you to 3,200 RPM) so I would like to stay with something with closer ratio gearing. (4L60E is a 3.06:1 first - THM400 is a 2.48:1 first gear) Overdrive is not that important for my purposes so 3 or 4 speeds are both workable.
Has anyone done something like this? Or does anyone have any suggestions on things that might work?
PS. To save questions about why I don't stay with the 4-speed manual, I had an injury to my left leg that makes working the clutch difficult.
Thanks
Last edited by kmcgowen; Jan 7, 2019 at 02:34 PM.
Race Director
Joined: Oct 2005
Posts: 12,470
Likes: 1,548
From: Camp Verde AZ
C1 of Year Finalist (performance mods) 2019
2017 C1 of Year Finalist
I've seen a lot of TH 350 conversions.
This may help:
https://i.pinimg.com/originals/bb/7d...5f631376a5.jpg
Doug
This may help:
https://i.pinimg.com/originals/bb/7d...5f631376a5.jpg
Doug
Race Director
Joined: Oct 2005
Posts: 12,470
Likes: 1,548
From: Camp Verde AZ
C1 of Year Finalist (performance mods) 2019
2017 C1 of Year Finalist
There is whole bunch of interesting stuff on that guys Pin page.
Doug
https://www.pinterest.com/pin/486248...39872/?lp=true
Doug
https://www.pinterest.com/pin/486248...39872/?lp=true
Thread Starter
3rd Gear
Joined: Jan 2009
Posts: 3
Likes: 0
Doug,
Thanks! That led me to some very useful info. It appears that a TH350 will fit and can be built to handle 500 ft. lbs. of torque, which should be plenty. The only issue appears to be that the TH350 needs a trans cooler.
If anyone has actually done this swap, I would love to hear how it went and any issues that came up.
Thanks! That led me to some very useful info. It appears that a TH350 will fit and can be built to handle 500 ft. lbs. of torque, which should be plenty. The only issue appears to be that the TH350 needs a trans cooler.
If anyone has actually done this swap, I would love to hear how it went and any issues that came up.
Racer
Joined: Jun 2009
Posts: 333
Likes: 22
From: Chicago Ill.
Th400
I put a th400 short shaft in my 62 . I had to remove one of the hex head bolts for the extension housing and replace it with a flathead cap screw and carve out some of the fiberglass for the ash tray. I made my own trans mount cross member out of some flat stock. I use an aftermarket shifter since I race the car.
Team Owner
Joined: May 2005
Posts: 31,497
Likes: 1,313
From: Huntsville AL
A TH350 can be build to handle that power and more. And every automatic trans should use a transcooler, regardless of whether or not it was factory equipped with one.
I replaced the cast iron powerglide in my 56 with a TH350. Pretty much a straight forward swap. The biggest issue was that I wanted to use the factory shifter, so I had to make a custom mount arrangement for the factory shifter.
I replaced the cast iron powerglide in my 56 with a TH350. Pretty much a straight forward swap. The biggest issue was that I wanted to use the factory shifter, so I had to make a custom mount arrangement for the factory shifter.
Race Director
Joined: Oct 2005
Posts: 12,470
Likes: 1,548
From: Camp Verde AZ
C1 of Year Finalist (performance mods) 2019
2017 C1 of Year Finalist
Doug,
Thanks! That led me to some very useful info. It appears that a TH350 will fit and can be built to handle 500 ft. lbs. of torque, which should be plenty. The only issue appears to be that the TH350 needs a trans cooler.
If anyone has actually done this swap, I would love to hear how it went and any issues that came up.
Thanks! That led me to some very useful info. It appears that a TH350 will fit and can be built to handle 500 ft. lbs. of torque, which should be plenty. The only issue appears to be that the TH350 needs a trans cooler.
If anyone has actually done this swap, I would love to hear how it went and any issues that came up.
Also, you could put one in the lower part of a modified splash pan behind the front wheels.
Doug
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Thread Starter
3rd Gear
Joined: Jan 2009
Posts: 3
Likes: 0
Pop Chevy,
My understanding is that all Automatic C2s used Poweglides. As far as I know the TH400 was introduced in 1968 on the C3. If that is the case, how did a C2 shifter work? Wouldn't it be missing one detent for a TH350?
My understanding is that all Automatic C2s used Poweglides. As far as I know the TH400 was introduced in 1968 on the C3. If that is the case, how did a C2 shifter work? Wouldn't it be missing one detent for a TH350?