Thanks Gil.
Gil found it before I did. The info I found is located
here. Most of the Mil and NAS part specs now must be purchased. Being a frugal RV flyer, I try to find the info for free that is also accurate.
NAS1149 series washers are the replacement for AN960 washers.
Letter codes that Gil talks about are:
C = 300 Stainless
D = 2024T3 Aluminum
E = A 286 High Temp Stainless
F = 1020 Carbon Steel
G = 4130 Alloy Steel
I used a lot of the D in place of the F that came with the kit.