Thumpic

I am re-working a mid 90s Pro-flex 853. I have no experience with a swing arm; how limber should it be? I am assuming it just pivots on a bushing over an axle and there aren't any bearings. I don't wanna get in over my head. It seems pretty stiff, but I can't imagine that it would move more than and eight of a turn at most......

I have read all the poop on the elastomer's and am hunting up replacement springs. So far I found a good one in a junk office chair. And I have a line on an identical one. I know these are not MTB springs, but I don't need a $100 titanium spring.....is there a "hidden" spring danger? Other than catastrophic failure??

Thanks.........