I might try using a crescent wrench, the purpose of which would be to bring #1 to TDC and #4 to BDC and insert something into the plug holes to measure the difference to determine stroke. After having Damper Dudes rebuild the dampener, I certainly don't want to muck up the crank snout. I could use the dampener bolt, but if I go beyond TDC, it probably will loosen when rotating counterclockwise.  

Here’s the link to a past thread giving some information on a crankshaft turning socket or tool.  I'll add that the crankshaft snout diameter for the Y is the same size as the SBC and 348/409 engines.  Modifying one of the SBC crankshaft turning nuts seems to be one of the easier options.

http://forums.y-blocksforever.com/FindPost160609.aspx

Lorena, Texas (South of Waco)

What size crankshaft rotation socket do I need? What is a good source for the socket, taking into consideration that it will be used infrequently (not professional grade).