If I read the parts book accurately, single spring with dampener.
Outer spring with surge damper and inner spring without. They were dual spring according to service manual.
As stated it really depends on how the heads were modified if they were. I used FP SS 72522 valve guide seals on my 66 heads, but I had new bronze valve guides installed. 2.2/2.5L seals.
I had my 1970 parts book handy and it list 3418491 as the Hemi valve spring. Looking at the picture in this eBay ad for allegedly NOS springs, 3418491 is a single spring with dampener.
