What do I need to do to convert to 134a from r12 , My 69 Bird is a factory Air Condition car with A-6 compressor. What have you done that worked.

Best to google it, but for starters replace the accumulator and change out all o-rings to the green type.

To convert a R12 system to r134 you need to replace the condenser with a larger one or one that has 20% more cooling surface area. You also need to replace the receiver dryer and flush out the evaporator and the rest of the system including the compressor. R134 requires the use of Pag oil not the mineral oil used with r12.
By the time you do all this with the factory parts you could have just replaced the whole system with a modern aftermarket system and been time and money ahead.

agreed

You could see if you can find a shop that works with this company, this product works, the trick is to charge initially to about 70% of the original amount and check performance, blends are never charged to 100% of original amount. So if the car says the charge is 16oz you charge to about 12oz.

http://www.icorinternational.com/hotshot.html

In addition to the other changes listed above, the POA valve will need to be recalibrated for the lower working pressure of R134a.