3 speed column shift to four speed on floor - The 1947 - Present Chevrolet & GMC Truck Message Board Network

LawMan02 · 10-18-2006, 08:58 PM

I've found a '72 Chevy K10 stepside for sale with a 350 and a 3 speed on the column. I have a '71 K20 with a four speed on the floor with a 350. Would this be a easy switch to swap the three speed for the four speed?

Longhorn Man · 10-18-2006, 10:19 PM

If they are both long wheel base, then it'd be very easy...remove and install.
If one is a SWB, then you'll have drive shaft mods to do.

I can't help but wonder though... why do you want to do this... onless you really work the truck, that 4 speed is driven like a 3 speed, so you aren't really gaining anything. It's not overdrive or anything.

LawMan02 · 10-19-2006, 10:58 AM

I'm just not a big fan of three speeds on the column. My cousin had a 4x4 with a three speed and it hung up all the time. I know that it was probably worn our and needed reworking but still like the reliable 4 speed.

**Yukon Jack** · 10-19-2006, 03:33 PM

When I swapped mine 3 speed manual out of my 69 K20 for a SM465, it didn't affect driveshaft length at all, the adapters are different lenghts and that keeps the overall length the same. My transfer case is the Rockwell T221 but I bet the adapters for the two trucks you have will also keep the overall length the same.

I was told when I did my swap that the bellhousing openings for the 3 speed manual and the 4 speed manual are different. I used the donor rigs bellhousing so I didn't measure and don't know if that is true. When I was contemplating the swap some on here agreed there was a differnce with the bellhousings, some didn't.

I hated my three speed due to it hanging up, especially in the winter.

Mike C · 10-19-2006, 08:03 PM

Mostly depends on whether you have a high hump cab or not. The low hump cabs did not come wiht the granny 4 speed to the best of my knowledge. I think all the 4x4's were high cab? I see both. My big block truck was high, my 70 Longhorn 4 speed truck high, my Jimmy high. But the 69 short step I have is low and the 70 3/4 long step is low. THe 69 auto and the 70 is 3 speed.

10-18-2006, 08:58 PM	#1
LawMan02 Junior Member Join Date: Nov 2005 Location: Saint Francisville, Louisiana Posts: 157	3 speed column shift to four speed on floor I've found a '72 Chevy K10 stepside for sale with a 350 and a 3 speed on the column. I have a '71 K20 with a four speed on the floor with a 350. Would this be a easy switch to swap the three speed for the four speed? __________________ 1972 GMC K2500, stepside, stock 350, 4 speed. Former F/D truck with 32,000 miles, no rust. 1973 Jeep CJ 5, 304, 33's with side pipes 2008 GMC 2500HD, CC, SWB, D/A, SLT

10-18-2006, 10:19 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: 3 speed column shift to four speed on floor If they are both long wheel base, then it'd be very easy...remove and install. If one is a SWB, then you'll have drive shaft mods to do. I can't help but wonder though... why do you want to do this... onless you really work the truck, that 4 speed is driven like a 3 speed, so you aren't really gaining anything. It's not overdrive or anything.

10-19-2006, 10:58 AM	#3
LawMan02 Junior Member Join Date: Nov 2005 Location: Saint Francisville, Louisiana Posts: 157	Re: 3 speed column shift to four speed on floor I'm just not a big fan of three speeds on the column. My cousin had a 4x4 with a three speed and it hung up all the time. I know that it was probably worn our and needed reworking but still like the reliable 4 speed. __________________ 1972 GMC K2500, stepside, stock 350, 4 speed. Former F/D truck with 32,000 miles, no rust. 1973 Jeep CJ 5, 304, 33's with side pipes 2008 GMC 2500HD, CC, SWB, D/A, SLT

10-19-2006, 03:33 PM	#4
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,686	Re: 3 speed column shift to four speed on floor When I swapped mine 3 speed manual out of my 69 K20 for a SM465, it didn't affect driveshaft length at all, the adapters are different lenghts and that keeps the overall length the same. My transfer case is the Rockwell T221 but I bet the adapters for the two trucks you have will also keep the overall length the same. I was told when I did my swap that the bellhousing openings for the 3 speed manual and the 4 speed manual are different. I used the donor rigs bellhousing so I didn't measure and don't know if that is true. When I was contemplating the swap some on here agreed there was a differnce with the bellhousings, some didn't. I hated my three speed due to it hanging up, especially in the winter. __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

10-19-2006, 08:03 PM	#5
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,727	Re: 3 speed column shift to four speed on floor Mostly depends on whether you have a high hump cab or not. The low hump cabs did not come wiht the granny 4 speed to the best of my knowledge. I think all the 4x4's were high cab? I see both. My big block truck was high, my 70 Longhorn 4 speed truck high, my Jimmy high. But the 69 short step I have is low and the 70 3/4 long step is low. THe 69 auto and the 70 is 3 speed. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax



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