When it comes to climate control the Gen IV uses separate high-capacity heat and cooling coils. When in heat mode the unit uses a dedicated parallel-flow copper/brass heater coil, and when it's time to chill out (sorry for that, but I totally set myself up, I had to do it) operation turns to an aluminum plate/fin-cooling coil. When the unit is in A/C mode, air bypasses the heater core, resulting in less restriction and increased airflow. A SPAL blower motor, with infinite speed adjustment, delivers maximum performance and comfort.
In terms of controlling the unit, things are as simple as turning knobs. Because the unit uses no vacuum or cables, it is controlled by a three-knob panel, which plugs into the Gen IV evaporator. The Streamline three-knob panel controls mode, temp, and intensity-and it's all at the turn of your finger wherever you decide to mount the panel.
7.The evaporator is put together for now, so it was time to determine a mounting location. | 
8.The way the Vintage Air unit is designed, it mounts to the backside of the firewall and to the inner cowl panel. | 
9.Therefore I placed the unit in position and took a few measurements in order to get my bracket dimensions. |
10.A key advantage to the Gen IV is the shape of the unit is ideal for vehicles with high transmission tunnels and stepped firewalls, like the '71. Because the evaporator is a stepped design, the bulk of it can rest against the firewall and the trailing end can rest along the tunnel. However, in order for that to happen in the '71 I needed to fabricate a few mounting brackets. I first cut out a plate to match the rear Vintage Air bracket. Then I welded legs to the new plate to push the unit off the backside of the firewall nearly 21/2 inches. From there I lined up the holes on the VA bracket and my bracket and drilled holes so I could weld bolts through the backside of my plate. | 
11.Here's my new bracket in place. I mounted the evaporator as high as I could and slightly to left, because I need room to run my A/C and heater lines from the bulkhead (which we will get to in a few steps) to the unit. Once my specific mounting location was determined for the bracket, I welded it to the firewall. | 
12.Next, I slid the Gen IV unit over the bracket bolts and mounted it in place. Then I measured the distance from the VA front bracket to the inner cowl, which was roughly 31/2 inches. |
13.With my measurements from the inner cowl to the unit, I could then fab my next mount. I used a block of wood to hammer the proper angles into the bracket. | 
14.Next, I welded in triangular trusses to each side of the mount for rigidity and drilled holes in the mount to match the front VA mount. Both of my mounts were made from 16-gauge sheetmetal. | 
15.Next, the mount was bolted to the unit and a line was drawn to pinpoint the mounting location on the inner cowl. |
16.Once determined, the upper flange on my mount was welded to the inner cowl. | 
17.Thanks to the design of the Gen IV evaporator, it's possible to create a sleek, compact A/C system tucked away neatly in your cab. | 
18.In order to feed the unit, new A/C lines and heater hoses must be brought into the cab. Keeping things clean and simple are Vintage Air's four-way bulkheads. I decided to go with a vertical bulkhead on the far left side of the firewall. In order to mount the bulkhead, simply cut out the paper template provided and tape it in place, using a level to make sure the bulkhead truly gets mounted vertical. Then use a center punch to locate the center of each hole and then drill out the holes using a 1-inch hole saw. |