55.2-59 57 chevy truck heater vents

[dsraven]

curious if anybody has a pic of the heater ducts on their 55-59. it's been many years since i took them off and they don't seem to fit very well. once i get them fit properly i can figure out what I will do for wipers cuz the wiper linkage needs to clear that stuff
thanks in advance

[dennislbrooks]

This is my 59 GMC stock heater, and I take you are referring to the 2 defrost port hoses?

[dsraven]

thanks for the pics. I was actually looking for info on the dash outlets. I have checked the FAM but don't see anything on how the dash outlets fit.
I had a 57 and a 58 that i am making one truck from. it's been about 15yrs since i took them apart and one had a deluxe heater, one was very basic. one has vac wipers and one had electric. i am using a donor vehicle and doing a frame swap so I'll be using the dash and pedals from the donor. that said, it is quite tight for the wiper motor from the donor to fit around the donor heater and venting, the donor dash structure and the donor wioper motor. i also gave away a bunch of the stock parts, including one set of defrost outlets, and I am wondering if the one set i have are from the other cab. i don't think GM would have made those parts different from year to year but you never know. i am finding it difficut to get the outlets i have fit into the original outlet holes in whats left of the origional dash-or the original windshield surround lip that is left on the inside of the cab.I ended up modifying the outlet holes a little and screwed the outlets I have. they will work, they will just be kinda in the way, lol.

[dennislbrooks]

When you say dash outlets are you referring the base of the windshield or where? My heater only vents from the bottom other than the 2 defrosts outlets. I will be up in there also when I get my aftermarket electric wiper motor.

Of course mine is a Fleet with no bells or whistles with vacuum wipers..

[dsraven]

I'm talking about the 2 seperate pieces the attach to the underside of the dash and connect to the actual heater unit with flex hoses.
Thanks for the interest and pics.
Surprisingly, my heaters looked different than the ones you posted. Maybe a Canadian thing.

[dsraven]

here are a couple pics of the dash with the defrost outlets installed. i guess, looking at the pics, they are prolly the right ones but they didn't really fit the original dash holes very well.
lower part of the firewall and the complete floor is from the donor vehicle. there is a huge heater unit to go in, as well as the structure that goes side to side and holds the heater/ac unit, the steering column and the dash pad.
fingers in pic point to the items of question, orientation is mostly what i'm wondering about. they fit very close to the firewall so wiper linkage will clearrance. the original firewall upper section still exists and you can see the bubble where the vacuum wiper motor sat. the electric motor that was in the 57 GMC doesn't fit in that space. i will use the electric motor, modified to mount, in that space.

[dsraven]

in the last pic you can see the limited space above the heater. the heater has an outlet on top, not in the pic, that is where those defrost vents will need to connect up to. that will be another home made adapter most likely. it may get capped with a short box that has outlets for hose on each side. we'll see after the wipers are set up and working.

[leegreen]

The AD version of those vents angles straight down, at least for '52 & '53 I have some loose in the shop if you want pictures/measurements.
They way they attach to dash is kinda floppy
The car ones of similar vintage turn at 90 back towards driver but appear to be much the same size.
I think there is a lot a variation on both the vents and heaters given the number of different factory and aftermarket options.

With what you have built so far I'd think about cutting those in half, welding the top part to your dash filler panel and making a compact manifold tube to join the two sides together than ends at a convenient point for the new heater box.
it could also work out to be support for wiper motor and arms

The flexible tubes get dangly over time, although mine were tucked up nice and tight now they are in the way if I need to work up in behind the dash - so I'd also add some points to secure any flexible tubing to.

[dsraven]

thanks for the advice, appreciated.
I am thinking of reworking or fabbing up some new vents that will be considerably longer and may exit in a couple of spots. i remember driving around in my dad's 59 in BC's winters. the defrost never seemed to clear the window very well. also, the donor heater had a big central defrot outlet cuz the windshield was much larger area than a TF truck, and also some side outlets at the end of the dash to help clear the door glass. i may incorporate something like that too. i cut the panels that i made to fit these defrost outlet vents but i can always fill those in or make them longer if need be. I will likely connect the defrost vents to the new heater configuration with some sort of rigid plastic tubing similar (or borrowed from donor parts) to the donor vehicle.I hav a plethora of donor tubing cuz I wrecked 2 donors. it is nice to have mock up stuff that I don't have to worry about getting scratched up tho.

[dsraven]

I also need to modify/cut that cast alu,inum piece behind the cluster so the wiper pivot lever has room to work. i may fab up some new linkage that clearances things better

[dsraven]

just as a side thought, you can see the large panel that bolts to the firewall and incorporates the master cyl/booster and also the pedals and column hanger on the inside. with the pedals removed you can see that there is a depressed artea that mounts the booster further into the engine bay. it also means there is more legroom on the inside. it might solve some issues with these short trucks for builders that have long legs or are looking for an easy brake pedal/booster/master cyl mount. there is provisions on the side of the pedal bracket to mount the LS drive by wire accel pedal as well. just a thought if you know anybody looking.

[dsraven]

here are some pics of the unit when out of the donor. the mounting plate has a bug hole and accordian grommet for the steering colum,n and also a big hole for the wiring harness to pass through
the master cyl in this case is set up for disc/disc option and has a bore of 1 inch. it's an 11 inch booster. the donor vehicle had front rotor size of 12 inches and a rear rotor size of 12.8 inches. this was one of the factors that helped me decide to do a frame swap, the donor came with rear 4 lin..373 posi. big brakes with discs all around, bigger than the MII i had my original frame set with. power rack and pinion steering. a large midship fuel tank with in tank pump and all the related plumbing done. strut front suspension (so easy to set ride height with the strut mounted independently of the control arms and there are custom struts available to lower or raise the front). the donor has coils out back, in my case, but has an air bag option from factory so all i would need to do is buy the GM iar bags and then set up a compressor etc or pick up a GM compressor and ride height sensors. it comes with frame mounts for the ride height sensors already built into the frame and even has the speedi clips waiting for screws. as well it comes with the power plant and running gear, an 4.2L Atlas inline 6 with as much torque and HP as the 4.8L LS I had in my original frame, this frame is also available with the V8 LS engine, so could convert to that with factory parts if desired later. all the wiring is there complete with fuse and relay panels. in my case I used the firewall and floor from the donor because my cabs were very rusty front to rear. the firewall already comes with the contours to fit around either engine option and the floor comes with contourts to fit the factory donor seats that incorparate seat belts, the center console, the center hand brake and carpet that fits the floor.
anyway, i could go on with reasons why it worked for me. not saying this is an option for everybody, cuz there is a lot more work to doing a frame swap than one would generally think. i also went a little further than most would as i am using the whole donor interior and the cooling/ac system under the hood, so lots more stuff to make fit. Finndiesel could likely attest to that as well as a few others on here that have done frame swaps. it was never my intent to make a show truck, just one thats quiet and smooth riding and can pull/launch my boat if needed. one day i'll get around to making a build thread.

[leegreen]

I was going to suggest making longer slots for the vents. Does the TF have interior window trim that covers the defrost? AD does, it has a single louver that blows onto window. And restricts airflow.

test your setup with the heater fan running before you button it all up. I retrofitted a 12V fan into AD heater housing, it was very similar in size to original but for some reason it is noisy, like a turbine unless I turn it right down. Which doesn't help the already weak defrost. I'll probably pull the whole heater out and redo it, maybe just make my own from scratch

[dsraven]

TF has a long strip that covers tghe vents. it snaps in and covers that depression area right behind the glass/rubber. since mine is a dash swap it is a little different. i will likely pattern and make a steel cover panel that fits more tightly around the vents, once i get things figured out.
Ill gety a pic of the dash and wiper set up later today. still a work in progress as far as mounting a wiper motor and getting some sort of linkage in place plus working around the monsterous dash panel behind the steering column, from the donor. cutting that aluminum or magnesium casting in the shop makes it look like the door was open and it blew snow inside. it is very suseptible to static cling as well.my shop vac looks like frosty the snowman, lol.
thanks for the advice, appreciated. maybe i'll start a new thread more inline with wiper motors and linkage.