I have a 72 small block car and the air doesn't work. This is my first Vette but I hear the factory air is useless. I'm looking for advise as to whether I should replace the factory system entirely or should I opt for an aftermarket unit.

I'm installing a Be Cool Alum radiator with dual fans, along with radiant barrier under the new carpet. I am also considering heat barriers on the firewall and trans tunnel. I live in the desert of Southern Cal and need all the cooling I can get for my new 383 stroker crate motor.

Any Advise?  

I installed all new factory on my 79 using AR-134 refigrent coool as can be. the deal is that if you DON'T put a insallation jacket over your AC lines you'll never be cool no matter what system you have  

Might as well give the old system a check to see how much $ it will take to rebuild the old system.  I just finished this project using the following:
1. Replaced 0-rings (less than $5 in parts)
2. Changed the old R-12 connectors (high and low) to R-134a connectors ($5 in parts) so I could use new A/C equipment to check the system.
3. Borrowed a vacuum pump and A/C gauges from Autozone for a week (free)
4. Hooked the gauges up to the car and the vacuum to the gauges to see if it would hold 30 bars of pressure for 24 hours AND IT DID

IF you are lucky your system might have just broken an o-ring and it will only take you $10 and some patience to find out.  This is a very common problem with old cars.  

I'll also add the other steps that got my system cooling again after getting this far:
5. Flushed the system with $10 flush and air compressor
6. Ordered and installed a new evaporator ($30) and orifice tube ($2)- this is a MUST every time you have the system open to air
7. Vacuumed the system for another 24 hours to remove moisture (preventative but recommended for most types of freon)
8. Fill with choice of freon ($30-80)

My compressor had a good amount of drag when I turned the pulley so I searched the yellow pages for a local A/C shop and had it rebuilt for an extra $150 but I consider this to be preventative.  

I'll also add that there are a whole bunch of options for freon that you can research.  it is still possible to find old R-12 which is probably the best cooling option.  There are also alternatives like Envirosafe 12a and Freeze12 that will work with R-12 systems.  Most people who use R134a are disappointed with the cooling until they replace the condenser with a larger aluminum upgraded condenser.

If your system is not holding pressure you can buy a single can of freon with dye to check your hoses for a leak.  It is possible to take your leaking hoses to a local A/C specialist and get them rebuilt with new rubber for about $20 per hose.  

My project took me about two weeks about $300.  I hope this saves you some time and money.  

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