Replacing the underdash heater duct tubing for 67-72 C10 Non/AC trucks

[HeavyHauler]

I am going to replace or clean the underdash heater duct tubing on my 1968 Chevy C10. This truck is a non AC truck.

How difficult is it to to remove the heater duct and tubing on the 67-72 C10 trucks and does anybody have any tips on removing them or links to a video about them.

I havent been able to find any info and I havent even peaked under the dash yet to see what I am going to be dealing with. .

[Willshook]

I just did this - super easy, but takes some patience and maneuvering.

I found inserting from the top worked best. Make sure you look at the plastic vents because they have a direction they should face.

I used the LMC Truck non- original tubes and they fit perfectly.

[RustyPile]

When I replaced mine, I removed the defrost vents, glove box and door.. This made access ever so easy.

[HeavyHauler]

Thanks for the tips guys! I believe some of the auto parts places like Oreillys, Autozone and Advance Auto carry defroster ducting so I will see what diameter the original ducting is and hopefully get some new ones.

[PbFut]

I did ac but some generic info. If you have the time, cut to length and place on the fittings and let sit over night or even a day or two. They will relax some. Also twisting on vs pushing straight on is way easier. Each fitting has 2 or 3 nubs on them to help hold tubing in place. You can push pull over these nubs but way easier to twist on. The steel coil in tubing acts like threads. The dash vents are brittle be careful. To work the vents off the sill, there are keeper nubs left and right, not fore and aft on the vent register. Better to reach up and slightly compress the tab the keeper is on than try to pry but that may be difficult. Those vets are brittle. I dropped one and broke a corner and of course the oem fit better than aftermarket.

[HeavyHauler]

This is good to know. I will make sure to be aware of the vents.