My research on the Internet has led me to believe that if you buy 91 Civic Si (d16a6) parts for the bottom (block) and 89 integra parts (d16a1, right marked001??
) for the top (head) you should be safe.
I just spent about $500+ buying bearings and rings and stuff for my ZC and bought d16a6 parts. Be careful, each bearing is custom fit and could be different sizes. They are differentiated by color swabs on the edge of the bearing and such, and the stampings in the block and on the rods...I would HIGHLY recommend a service manual.