Vanagon GL 86, 2.1
We need a new compressor... when one thing goes wrong, others come along, but it's worth it!!!

Here is the question: which A/C compressor model do we need? The suppliers sell SD508 & SD709. Our van has SD510 (see picture). Actually, numbers and letters that are on the compressor include

510S21 (embossed on body, indicating model?)
9150 label which was stuck over Model# U 96773 (on main label)
Serial#: 00027702971 (on main label)
Q (on cylinder head, indicating cylinder head type)
A1A68UM (on clutch)

It looks like our choices may be

SD510  (R12/R134)
SD7H15HD  (R134)
SD7H14HD  (R134)

SD709  (R12/R134)
SD7H15  (R134)

SD508  (R12/R134)
SD5H14  (R134)

So, which one is it?

Note that we converted to R134 a few years ago when we were supplied with the 510 one.

georgios