as far as I know, the only way to check if they are open or closed is with the head off. Look inside the chamber whare the valves are, the open chamber head is somewhat bored out (concaved),
the closed chamber is flater, more to the surface to the head, makeing more combustion.
like coupe3w had said, the circular (open) is hallowd out, and the closed (quench) is filled in.
There were some posts about 4 months ago with pictures and a ton of responces. good luck finding them!!!!
as far as stroker???
i dun no.
I just had mine built, and the cam is an RV, i'm not real sure how to read the specs on it, but it seems a bit mellow. My builder recamended this cam because I have an automatic and it wouldn't idle for ****.
I just put on Holly 750, on top of an edelebrock performer, but it only gives me 5500 rpm then it starves. I'll be changing it soon.
what I have in my rig is;
351C 4bolt mains
4v closed chamber
bore .030 over
Keith Black flat tops
MSD 6A, Mallory dist.
Holly 750, Performer intake
headers, 2.25" duals straight back
with the exception of the intake, I like what I got. for my light '56 f-100 it moves.