All factory A/C equipped models from 86 on already have the more
powerful fan. All Syncros do also, whether they came with A/C or not,
AFAIK. Hopefully someone else will answer your other questions regarding
the A/C.

Mark

Christopher Gronski wrote:

>I drive an 86 syncro westy and I want to add front AC to my existing
>rear AC. My current (seized and leaking) compressor is a SD510.
>
>Bus Depot lists the SD508, the SD510, and SD709 for the '86 model
>year, all are the same price. Am I correct in assuming that the 5
>series compressors are 5 cylinder and the 7 series are 7 cylinder
>(hence the 7 series would be more powerful. I assume I would just have
>to change the fittings. Is there another difference? Are they
>interchangable?
>
>Since I am adding the BEHR unit up front I thought it might be prudent
>to upgrade to the SD709 along with the upgraded 253 260 403 two fin
>section condensor (versus the 255 272 413A condensor which is single
>fins). Again I am wondering if the condensor is interchangable.
>
>Lastly is the radiator fan. Volks cafe lists a fan assembly
>251.959.455M at $445.00
>which seems a little steep. Would I have to buy this whole setup (plus
>the condensor) if I wanted to upgrade the fan?
>
>Any advice would be appreciated...
>
>
>