What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

1972 GMC K5 then and now

Overview Gallery Discussion
I did get the new springs in and the truck back on the ground.
I’m using Procomp 13311. They are 52” long and 4” lift. This time I’m keeping the overload spring on the bottom and hope the last more than a couple years and still ride decent.
IMG_1726.jpeg
IMG_1728.jpeg
IMG_1729.jpeg
 
72gmck5 said:
I’ve been running these same type of springs without the overload but this is the 3rd set so trying it with the overload for a change.
Click to expand...

I ran the overloads on the first set, I don’t think it made a difference for longevity. Bumps are more important. On my third set and they’re pretty hammered.
 
Since I had to pull the transfer case to swap the adapter, I figured I might as well do some cleaning and upgrades. I had a JB fab twin stick kicking around for a while it’s finally the time to add it. I didn’t have modified shift rails and so I ordered a set.
At this point it was close to my birthday and my wife tried to surprise me with a car related gift. Turns out we got me the same thing. Two sets of shift rails showed up at the same time.
 
Last edited:
Tore down the transfer case and cleaned it up. Then started on the twin stick rails. IMG_2016.jpeg
As I was getting the rails in, the front control rail selector fork fell into the case making it so I had to pop the back cover off. IMG_2018.jpeg
Turns out there’s some big snap ring in there and luckily I had just picked up a set of snap ring pliers that came in handy.
IMG_2012.jpeg
 
I got the shift fork in place and put it all back together. And tried shifting the rails, only to find out the font rail was binding. Turns out I had turned the gear around in the transfer case when I put it back in. The synchros were on the wrong side :doah:
IMG_2020.jpeg
Flipped the gear around and put it back together.
Then put the twin stick set up on.
IMG_2022.jpeg
 
I put the shifters in and it took a minute to adjust the linkages for smooth operation.
The adjustable detents are neat, making it so I can dial in engagement feel.
I did have to larger hole in the trans tunnel than these needed so I made a cover plate the boot could attach to.
IMG_2049.jpeg

IMG_2060.jpeg
 
Last edited:
At this point I turned my attention to some of the other parts that needed work. I had previously added a CS130 alternator that was supposed to put out 200ish amps. And it might have but didn’t get anywhere close to that at idle. My truck kept threatening to die from lack of power when I’d stop at a light and have both my fans running.
So after looking at the outputs of different alternators, I decided on a CS144. I happened across what seemed like a fairly new rebuild at the junk yard a while back and grabbed it for the swap

IMG_2053.jpeg

The stock adjuster bracket didn’t have enough throw on it and the larger alternator was too close to the brake MC along with the valve cover. So I added some spacers to push the mount out and grabbed a different adjuster bracket I had kicking around.
IMG_2062.jpeg
By pushing the alternator out a bit I had to swap the belt position for the AC compressor and alternator. When I did that the AC belt was running into the lower radiator hose. So I then had to look at how to bend the hose or keep it out of the way. While I was checking I found the hose was wearing against the frame and was almost though :eek:
IMG_2052.jpeg
I ran over to the parts store and grabbed a new hose. The replacement had an extra inch or two on the radiator end that I had trimmed off the old hose at some previous date.
With that extra length it put a curve in the hose around where the belt runs and so no interference. Almost like someone planned it like that. :D
IMG_2054.jpeg
 
Last edited:
With belts and hoses figured out I was able to start and run the truck but it didn’t run very good.
I took it for a drive and the truck drove, shifted, maintained speed, but was a dog and burning really rich.
IMG_2068.jpeg
Haze in the headlights was smoke.
Tried messing with some of the fueling setting on the Fitech and nothing changed. It was sitting at a 10.4 AFR and wouldn’t lean out.
Last year I had timed it, put in new spark plugs after replacing the ecu on the Fitech.
@ashman had lent me a smoke machine and I decided to hook that up to see if i had a leak causing the O2 sensor to read funny.
IMG_2069.jpeg
Turns out the flex joint I put in was leaking pretty much all the way around.
 
Not having a lot of gen 1 k5 experience I need to ask, is the short water pump factory for a 72 ? I was thinking GM stopped using the short water pump in 69-70
 
Wes Harden said:
Not having a lot of gen 1 k5 experience I need to ask, is the short water pump factory for a 72 ? I was thinking GM stopped using the short water pump in 69-70
Click to expand...
I’ve noticed whenever I go to get parts that it’s on the rarer side. The water pump is one I got with the truck. It was new at the time I rebuilt the motor so it’s what I went with.
 
Correct. I got the truck while in high school from my shop teacher. The truck had been torn down for a restoration and was sitting in boxes. I’m assuming the parts were original, but they could have been mixed over the year. Water pump, crank, alt, and PS were all there. It’s an AC truck but I never had a compressor until the vintage air. If I was starting over I’d probably go long WP just for easy access to parts.
 
You must log in or register to reply here.

Latest Posts

Top Bottom