I've never seen any reference that stock B or RB engines in any configuration used a Hemi valve spring.
6-paks had street hemi springs. they had a yellow stripe vs the hipo wedge being all red. they were a high rate spring which was common back in the day. actually a fairly crummy spring but we used them not knowing better.
The factory parts manual will show the part numbers used, that would be the reference needed. Looking at my manuals I see the following.
1969
Hemi - 2899549
6bbl - 3418491
1970-71
Hemi - 3418491
6bbl - 3418491
So the answer is both yes and no. In 69 the 6bbl did not use the Hemi springs, in 70-71 they did.