R12 works much better in a Pantera without modifying the system by using O-ring fittings and new 134 hoses. But 12 is very expensive so be prepared to spend 75.00 to 100.00 a pound and finding a shop in Calif. may be tough. Look on E-bay for real r-12
http://www.ebay.com/itm/R12-Refrigerant-/272787228441
Good luck.
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