I searched but couldn't find the exact answer I'm looking for. On Rock Auto I found a couple of OEM replacement timing chain sets for my 400. These have steel gears instead of nylon. Do these come retarded like the original factory sets or are they "straight up"? Here's a link to the one I was looking at.
https://www.rockauto.com/en/moreinfo...=5031156&jsn=3

 

Just order one for a 1970 351 Cleveland that way your sure it's a zero set.

 

Degree your cam, its the only way to know for sure. I prefer gear drives myself, but nothing wrong with chains.

 

If you get a performance chain from Summit racing it should be zero. Otherwise you may not know what you get. They will usually tell you if it's a straight up set.