Where to buy dash A/C parts-1994 georgie boy P30

That block type expansion valve was used on many Chrysler products in the 70s & 80s. If your receiver dryer has a dry break fitting on one end and a 3/8" tube "O" ring on the other, then buy a dryer with 3/8" tube "O" ring fitting on both ends, cut the dry break fitting off the hose and buy a 3/8" tube "O" ring X #6 barb hose fitting to replace the cut off fitting.
If this is beyond your scope, take my comments to an old time AC person and he'll know exactly what to do.

Richard