picked up a 340 long block w/out specs

If I were to buy a car would I disassemble the engine just to see what's inside?

Hell no....

Sometimes we get so anal about this stuff...we really do.

In the oval track world few, if any, guys buy a motor and pull it apart. We buy the stuff to race... Most give it a once over, check the valves, might swap a carburetor and put the thing on the track.

GM crate engines are like that (you mostly know what your buying) but is true with "open" motors, too. Might give a guy some smiles if he knowsw the engine builder was but means very little in the grand scheme. Either it runs or it doesn't.

I got over all that hand wringing over small details long ago.

Just trying to make your lives a bit easier...