Timing set questions

Look, man, the top sprocket turns 1/2 the speed of the bottom one. That means if you rotate the crank 1 turn they WILL be matching

Also, the way you have it there is no1 ready to fire. Several timing sets (engines) are actually on no6 ready to fire (compression) when the marks are "dot to dot". I don't know about Ferd, but chev and Mopar are that way. Why they are made that way is beyond me.

So far as chain slack, might be due to variance in engine casting/ machining, OR the engine may have been line bored at some point. I'm told you can buy undersized chains but have never dealt with them.

If this is not a performance build, and especially if you did not "degree" the cam anyhow, a little slack will "never know."