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74 corvette AC upgrade

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Old Mar 11, 2026 | 08:15 PM
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Default 74 corvette AC upgrade

looking to upgrade my 74 vette with factory air, that is whats left of it. I have looked at Vintage air and classic auto air but not happy with the look of there controller. I talked to both, and at this time thay do not have a conversion to use original controller with there latest systems. I had originally planed on using Original air under hood kit but they are no longer in business and classic auto air does not supply kit andmore. Any thoughts.
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Old Mar 11, 2026 | 10:11 PM
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Yes, read my thread, 73-E77 Air-Con upgrade. Sorry I can't seem to post links on my phone.
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Old Mar 13, 2026 | 09:49 AM
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Dave,

My 79 originally came without AC, and there were no drop in aftermarket kits available at the time I decided to convert it over to an AC car. I sourced all the parts I needed from E-Bay and Forum Members. You can follow my conversion (which is still in progress) at my restomod link below. I'm not sure what it is you are upgrading, but as you may know, the climate control panel is used to actuate diverters to channel air through different duct passages, and control the fan speed. These diverters are all located on the heater core housing, which you can remove and rebuild. The one I purchased needed a lot of work but was pretty straight forward to repair. Once those are functioning correctly, you can purchase a compressor, evaporator, condenser, etc. compatible with R134a if that's your goal. The original vacuum control system works just fine with these versions of compressor. So it seems you may have two paths to pursue, rebuild/repair the original control system, and upgrade the refrigerant components. I hope this helps.

MajD
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Old Mar 13, 2026 | 10:18 AM
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Originally Posted by 4-vettes
Yes, read my thread, 73-E77 Air-Con upgrade. Sorry I can't seem to post links on my phone.
Here's @4-vettes thread, for those stuck on their phones.

https://www.corvetteforum.com/forums...n-upgrade.html
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Old Mar 13, 2026 | 02:19 PM
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I rebuilt my AC with all new Sanden style compressor, condenser, evaporator and accumulator for a 78, ( to get rid of the VIR valve). I ordered fittings and hose and made new lines. I
still run the original controls in the car. Works great with R134 and I can service it myself.
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Old Mar 13, 2026 | 07:56 PM
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VIR was 73-E77. Late 77 and up do not use the VIR .
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