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| | | | Joined: May 2012 Posts: 5 New Guy | | New Guy Joined: May 2012 Posts: 5 | Can anyone tell about swaping trans. on a 65 c10. I have the stock 4 spd. with the granny low. | | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | What do you want to take out & what do you want to put in?
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | | | | Joined: May 2012 Posts: 5 New Guy | | New Guy Joined: May 2012 Posts: 5 | the truck has a m420 in it now, and i would like to put an m21 in it. I am guessing that i would kneed a new cross-member at least,but not sure if that is all it would take for this swap. Any input wuold be greatly appriciated. Thanks | | | | | Joined: Nov 2002 Posts: 1,002 Shop Shark | | Shop Shark Joined: Nov 2002 Posts: 1,002 | What emergency brake do you have?
Is it the one with the lever on the floor or under the dash?
Larry
I don't own a vehicle that isn't old enough to drink.
| | | | | Joined: May 2012 Posts: 5 New Guy | | New Guy Joined: May 2012 Posts: 5 | | | | | | Joined: Jul 2006 Posts: 187 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 187 | I'm not sure what the transmission overall length is but going from an SM420 to a M21; you'll probably need a longer driveshaft. If the yolk splines on the front of the driveshaft are different then you'll need a donor driveshaft or yolk. You'll probably have to fabricate a crossmember and modify clutch linkage. | | | | | Joined: Apr 2005 Posts: 2,098 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 2,098 | The transmission in a 65 C-10 does not mount to the crossmember.
It hangs by the 4 bolt mounting tabs on the bellhousing. The bellhousing mounts to the rear crossmember. The M21 is longer than the SM420. The SM420 drive shaft bolts directly to the trans and has a slip joint in the front section of the driveshaft. The M21 uses a driveshaft with a splined slip joint on the end that slides into the rear of the trans.
A competent drive line service can make one up for you. You will have to cut a hole in the floor for the shifter, otherwise no other changes are necessary to make this conversion.
Fred
1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine
| | | | | Joined: May 2012 Posts: 5 New Guy | | New Guy Joined: May 2012 Posts: 5 | So i should be able to bolt the m21 to the bell housing and not have to alter the clutch linkage? | | | | | Joined: Apr 2005 Posts: 2,098 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 2,098 |
1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine
| | | | | Joined: May 2012 Posts: 5 New Guy | | New Guy Joined: May 2012 Posts: 5 | Cool, thanks so much for the info., I just picked up a 66 big window and I have so many questions running through my head, I hope you all don' t mind me buggin you with lots of dumb questions. Thanks again!!
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