3 speed column shift to four speed on floor

[LawMan02]

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]

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]

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]

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]

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.