M_Boats: setting up new mast for M15

I'm setting up a new DM-4 mast on my 1981 M15. Does anyone have the height of the installation holes from the step to the hounds? My existing mast was not stock (16" removed) so I don't trust the location. Also, in some pictures of other M15's I've seen the shrouds attached to the forward hole (of the two) in the chain plate. I've also seen them in the stern hole. What is the preferred position of the two? Would you swap them between the two holes due to the anticipated conditions before going out for the day? Norm M15 #172