Is there an expansion valve that will fit a 87 300dt that would be more efficient in a R134a system? I know R12 would be preferable but am just getting parts together for a makeover and will be using R134a. Any suggestions? Thanks.
Bud

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1987 300D Turbo, 175k mi., 1998 BMW 323i Convertible, 1997 F250 4x4 7.3L PSD