Engine Is Out, Now What?

Ill second the core plug R&R and a good block flush as well as valve seals. I took about a 1/4 lb of fine dried sludge from the water jackets of a 64 273. The core plugs in the back were packed solid, I had to get a screwdriver to loosen it up to flush out. I used a hose, then a pressure washer in the front plug and blew everything out the sides and back core holes. Nasty work as the stuff flies everywhere. I found what looked like a coat hanger sized wire in my 67 slant water jacket. wtf?
Valve seals were gone. I found them all in pieces in the oil pan. They just get brittle and break apart over 50 years. timing chain is cheap insurance to change out.