Hi Mattias,
I just ran across your post and saw that no-one has answered it. Perhaps I can still help you.
WIPER ARMS
The 1966 Mopar B-Body was a 1-year only arm.
It was polished stainless steel stem with a chrome base.
The Left and Right are slightly different angle at the tip.
You will know that you have the correct arms if you see the letter L stamped into the stem on the LH side and the letter R on the RH side. OE Mopar part numbers are 2580925 for the LH and 2580926 for the RH.
It is a bright arm that fits a 5/8" shaft and has a 1/4" bayonet end on it.
WIPER BLADES
The Mopar part # listed in the catalog for 1966 B-Body wiper blade is 2771906.
I am not aware of any reproduction blade that is 100% correct for the 1966 B-Body.
But, I do know of several different styles of reproduction 16" blades currently available in the aftermarket that are close and that should be considered era-correct service replacements. To be most authentic, the blade will be a 16" blade with polished stainless steel finish as was factory original for most 1966 models. And, you will need a bayonet connector to fit your 1/4" bayonet arms.
There is an Aero style blade on the market that has an anti-lift feature, that is a double-bridge style blade that would be very similar to Mopar part # 2771913. It would fit and would look era correct on your car. These are marketed currently as part# 3980353.
There is also an ANCO style 16" polished blade being reproduced.
It is a standard rainbow type blade, (rather than double bridge) but it has a polished finish and would also be a correct service replacement for the era. Something that someone would have found at a parts house or gas station back in the 1960's. So, if cosmetic appearance is not critical, then it should serve as a functional replacement. It is currently marketed under part # 153391.
Hopefully this serves as some help to you in your search for arms and blades for your '66.
Best regards,