The GMC CCKW

Can anyone outline the issues I will be facing IF I try swapping the 4 speed transmission (Stock Chevy 1.5 tonner) with a 5 speed from a CCKW?

I am considering it now, basically as my origianl tranny is in need of a rebuild. If I gott pull it why not consider this swap now...

Does the 5 speed bolt right up in place of the 4 speed OK? Mounts are all the same or are there modifications needed just to mount it up?

Modifications to floor? Driveshaft length?

I am running a later model chevy 235 full pressure engine of about 1957-1960 vintage.

Do I need to change clutch disks becuase output shaft splines are different or are the shafts the same from the chevy to the CCKW?

I think the rear dirveshaft yoke might be different on the chevy vs the CCKW requiring a custom made intermediate shaft being made up with a CCKW u-joint on one end and the oprigianl u-joint to transfer case on theo ther?

Please advise!!!

THE FLOOR.......................

Take a CCKW starter linkage spacer (about 3" high), the one that is mounted to the bellhousing that holds up the starter linkage that crosses the bellhousing and set it on the floor by the gas pedal in your Chevy. Then sit in your chevy and ask yourself: can I operate the gas pedal if I have to make a box over the top of the CCKW 5 speed tranny that is this high right in front of the gas pedal?

The clutch is not a problem. The bolt pattern is the same. The driveshaft to the xfer needs to be shortened and needs to have a yoke on the front that will accept the larger CCKW U-joint (not a big issue).

THE FLOOR.......................

I've had a 5 speed CCKW trans in mine for about 18 years and am very happy with it... I have large feet size 13. I drive with my heel on the floor or on the top of the tranny:


Shot with E900 at 2007-09-22

Heel on top of trans:


Shot with E900 at 2007-09-22

Shot with E900 at 2007-09-22

Home made adapter plate for T case levers:


Shot with E900 at 2007-09-22

Shortened jack shaft:


Shot with E900 at 2007-09-22

The shif lever needs to be shortend and I bent mine like this:


Shot with E900 at 2007-09-22

thanks for the inpit, both CHevy43 and Dr. Duece.

Chevy43: What kind of road speeds are you seeing?

Are you running the stock sized tires or larger?

How is the 5 speed transmission compared to the stock 4 speed meaning shifting wise.

the 4 speed seems to be loosey-goosey at best.

Is the 5 speed noisier or less noisy than the 4 speed?

TO both of you: Do you hear lots of drivetrian noise while driving?

Like the gears in the rear, tranny transfer have lots of backlash and the times between deceleration and acceleration are noisiest with what I want to describe as metalic slop.

Anything like this normal?

I remember my old Dodges were like this. However, its been awhile since owning a closed cab. Closed cabs seem to resonate and amplify the noises anyway.