Or convert the cowl vent to electric.

 

I made my own. It will house the vents and probably the controls as well.

 

Here is the fiberglass one that Mid Fifty sells. It is fiberglass. Not a bad piece. I see they make a steel one now. The ends makes a nice contour. Right side is clearance for the glove box. Marten, yours looks good.

 

i gave that a thought, but decided not to. Trying to keep the cost down.

 

I used the one from Vintage Air. Its rather flimsey, so I installed a couple of braces where needed. I used the ABS kick panels from MidFifty that bulge out for mounting speakers so I had to cut about 2.5" out of the the Vintage Air panel and join it back together so it would allow clearance for the right speaker, and still fit to the right of the OEM steering column bracket. You will see 2 rows of screws where the joint is. The top mounting flange is just barely wide enough to fasten under the lower lip of the dash and still allow clearance to open the glove box door. This lip needs to be about 1/2 to 3/4" wider. I purchased mine some time ago so they may have changed the design by now. I also have a manual cowl vent, and this design allows it to work without going to electric.
Note: ( I would assume this applies to any dash extension.) Make it removable. Any work that needs done under the dash cannot be accomplished with the extension in place as there is minimal room to work, or even see what you are doing since the firewall is so close to the dash. I had to remove mine a couple of times to make wiring circuit modifications, and once to address a wiper motor grounding issue. If you use the Vintage Air system the AC thermostat thermocouple will need to be installed into the top of the evaporator housing after the switch panel is mounted in the extension. This is all but impossible with the extension bolted in place. Matter of fact, it is almost impossible once the evaporator housing is in place. Test fit the probe before installing the housing for proper depth of insertion.
Another Note: I did not install any glove box behind the door. This is the only access to the valves and hoses at the right end of the HVAC box, and the only access to the vent and defroster hoses. This system really fills up the space.

 

... from Facebook () Donald Walker;

 

If you look at the 2 panels your control is mounted next to the column where as mine is by the ashtray. Where mine is mounted it was difficult to attach the wiring to the control.
The prongs were almost hitting the evap housing so i had to bend the prongs down about 45 deg to attach the wires.

 

Yes, I noticed the difference. Not much space left when installed on either. Was your upper attachment lip wide enough to set it back for clearance for the glove box door? The lip on mine, as I remember was only about 1".

 

Mine is only about 1"...I havent tried the glove box door yet. I hope i dont have any issues.

 

This brings me back to a question a couple weeks back - To vent or not to vent with Vintage Air set up or any other system? Condensation, evaporator drain hose, fresh air to heater? Please help!

 

There is no provision to intake outside air with the Vintage Air system, it simply recirculates the air in the cab. I installed a block off plate over the louvers on the right side of the cab. I would think that given the way we seal up our cabs when we trick them out with carpet and interiors, that even if there was a way to draw in outside air, there would be no way to exhaust that air. Back when these truck were new, there were plenty of places for the air from the Fresh Air heater to escape, but without installing exhaust vents of some kind there would be no way the air could escape, thus there would be no air movement. I suppose one could cut the back of the cab and install rubber vents like modern trucks use, but I see no good way to force the HVAC fan to draw in outside air.

As for the evaporator drain, there is a provision for the drain tube to exit the cab out through the firewall near the location that the AC and Heater tubes enter and exit. I dropped the tube down the front of the firewall and terminated it near the frame.

 

I blocked off my vents both the cowl and right side vent. I have windows that go up and down for fresh air. When I was talking to others, everyone recommended an AC system because of the heat from the motor and sun through the glass would make things hot.

 

Thrifty, did you use this one? I bought one and returned it, did not fit at all. I seen a post a while back that they still have the same problem, not even close to fitting nicely.
And thanks for the complement, I really happy with the way it turned out.

 

My underdash extension was bought 5 years ago? I only had clamps and a few bolts holding it together. So I really can't say it was a good fit.It was basically to get a mock up. I think I would rather have the metal one. Before I make a call on it I will re install it and check more closely. I will have to call Diane at Mid fifty and find out if they have gotten any better. Sometimes their vendors are not consistent. Here is the short glove box they make for the A.C

The gap seemed good for the kick panel


not much room but it's something