Bought some 243 heads....Got a few ?'s

[Kros383SS]

So I bought some used 243 heads with 27k miles on them with the yellow springs that came off a Vette. The heads look damn good, my ? is how do I tell if these are actual vette heads that had the sodium filled valves?
Can I run these as is on my 6.0 or would a P&P be better?
Also If I run a thinner heads gasket to bump comp, can I still use 7.4 length push rods?
Cam will be installed when I do the heads and will be bought from EPS.

I have enough $$ to buy the cam and do the install but If I go any further(depending on how much a P&P is) it will dip into my $$$ for my paint job which is just around the corner.

You can see what I have in my sig and now the truck will primarily be driven to car shows and I might hit the track a time or two.

[George C]

only vette that had those valves are the Z06 and they would be longer in length. all other 243s use standard length valves and standard valves.