OneShot
Full Access Member
- Joined
- Oct 1, 2014
- Posts
- 91
- Reaction score
- 50
- Location
- Indiana
- First Name
- Paul
- Truck Year
- 1979
- Truck Model
- c20
- Engine Size
- 350
'Afternoon fellas.
This morning I went through the process of upgrading the blower in my '79 C20 standard cab long bed. I's been below 0 here for two weeks now (central Indiana) and the heater in my truck struggled to keep the cabin at a passable temperature on long interstate drives to and from Purdue (West Lafayette, IND).
I saw a couple of threads on another chevy forum (links below) about upgrading the blower motor to a mid-90s extended cab blower, but I hadn't seen anybody document their upgrade, so I want to do that for you now. These other sites have mixed reviews about the effectiveness of this upgrade. My stock motor may have been a little shot, I don't know, but after this upgrade the heater in my truck blows twice as hard as it did before. It's absolutely incredible.
Here's those links I talked about.
http://67-72chevytrucks.com/vboard/showthread.php?t=468297
http://67-72chevytrucks.com/vboard/showthread.php?t=166446
And here's how to do it.
Go to the store and get a blower motor for the following pickup. I went to Auto Zone and it was like $25.
1994 Chevy K2500HD Ext. Cab 4x4 5.7L
Pull the old blower out of the truck (in the engine compartment, extreme passenger side. 5 bolts and a wire come off to get it out) After getting the blowers out remove the squirrel cages by taking off the single retaining nut and pulling it off the shaft. You might have to gently heat the plastic to get it off of the shaft. I used a propane torch at a responsible distance.
They will look like this side by side (old on the left and new on the right).
You have to put the old squirrel cage on the new motor in order to fit into the stock shroud. The new blower is longer (as seen above) and will hit on the intake of the shroud against the firewall. Thankfully the shafts are the same size and the bolt pattern is exactly the same between the motors. Unfortunately, you have to slightly modify the old squirrel cage to fit further down on the new shaft in order to get the clearance needed. As seen above, the new motor sticks farther out into the shroud than the old one, so the squirrel cage has to be pushed back.
First, remove the clip on the new shaft that holds the squirrel cage up further on the shaft. This should just slide off.
Then, find a drill bit that's the same size as the shaft major diameter. The old squirrel cage will only slide on as far as the ground section of the shaft extends, which is not far enough. To make up this extra 1/8 inch or so, you have to drill out a bit of the old squirrel cage. Be very VERY careful doing this! If you drill too far, the squirrel cage will not engage the shaft and you will need to get a new one.
Before drilling:
After drilling:
I drilled down about an eighth of an inch. If you're really paranoid, try it in smaller increments and test fit into the shroud until it no longer hits the back of the shroud.
After this, just slide the old squirrel cage on to the new shaft. Some unthreaded shaft will be left sticking out the top. Just use the old washer trick to cover this distance and tighten back down with the new retaining nut as shown below.
When bolting it back in, the power wire will be at approximately the 12 o'clock position instead of the factory ~3 o'clock position. Otherwise, it bolts straight up. Looks like this.
And that's it! I turned it on for the first time and even without the engine running it blew like crazy. We will see how it performs once it gets down to -30 again.
Hope someone finds this helpful in these cold months. Happy modding!
This morning I went through the process of upgrading the blower in my '79 C20 standard cab long bed. I's been below 0 here for two weeks now (central Indiana) and the heater in my truck struggled to keep the cabin at a passable temperature on long interstate drives to and from Purdue (West Lafayette, IND).
I saw a couple of threads on another chevy forum (links below) about upgrading the blower motor to a mid-90s extended cab blower, but I hadn't seen anybody document their upgrade, so I want to do that for you now. These other sites have mixed reviews about the effectiveness of this upgrade. My stock motor may have been a little shot, I don't know, but after this upgrade the heater in my truck blows twice as hard as it did before. It's absolutely incredible.
Here's those links I talked about.
http://67-72chevytrucks.com/vboard/showthread.php?t=468297
http://67-72chevytrucks.com/vboard/showthread.php?t=166446
And here's how to do it.
Go to the store and get a blower motor for the following pickup. I went to Auto Zone and it was like $25.
1994 Chevy K2500HD Ext. Cab 4x4 5.7L
Pull the old blower out of the truck (in the engine compartment, extreme passenger side. 5 bolts and a wire come off to get it out) After getting the blowers out remove the squirrel cages by taking off the single retaining nut and pulling it off the shaft. You might have to gently heat the plastic to get it off of the shaft. I used a propane torch at a responsible distance.
They will look like this side by side (old on the left and new on the right).
You must be registered for see images attach
You must be registered for see images attach
You have to put the old squirrel cage on the new motor in order to fit into the stock shroud. The new blower is longer (as seen above) and will hit on the intake of the shroud against the firewall. Thankfully the shafts are the same size and the bolt pattern is exactly the same between the motors. Unfortunately, you have to slightly modify the old squirrel cage to fit further down on the new shaft in order to get the clearance needed. As seen above, the new motor sticks farther out into the shroud than the old one, so the squirrel cage has to be pushed back.
First, remove the clip on the new shaft that holds the squirrel cage up further on the shaft. This should just slide off.
You must be registered for see images attach
Then, find a drill bit that's the same size as the shaft major diameter. The old squirrel cage will only slide on as far as the ground section of the shaft extends, which is not far enough. To make up this extra 1/8 inch or so, you have to drill out a bit of the old squirrel cage. Be very VERY careful doing this! If you drill too far, the squirrel cage will not engage the shaft and you will need to get a new one.
Before drilling:
You must be registered for see images
You must be registered for see images attach
After drilling:
You must be registered for see images attach
You must be registered for see images
I drilled down about an eighth of an inch. If you're really paranoid, try it in smaller increments and test fit into the shroud until it no longer hits the back of the shroud.
After this, just slide the old squirrel cage on to the new shaft. Some unthreaded shaft will be left sticking out the top. Just use the old washer trick to cover this distance and tighten back down with the new retaining nut as shown below.
You must be registered for see images
You must be registered for see images attach
When bolting it back in, the power wire will be at approximately the 12 o'clock position instead of the factory ~3 o'clock position. Otherwise, it bolts straight up. Looks like this.
You must be registered for see images attach
You must be registered for see images
And that's it! I turned it on for the first time and even without the engine running it blew like crazy. We will see how it performs once it gets down to -30 again.
Hope someone finds this helpful in these cold months. Happy modding!
Last edited:
