When doing a rear disc conversion on ABS drum brake Honda civic, you need the proportion valve part number 46210-s04-852.
A link to the part online:
http://www.hondapartsnow.com/genuine/ho ... 4-852.html On local Honda civic 97-98 SiR it has a H at the end, and on 99-00 SiR it has a L at the end. On the drum cars it will most likely have G at the end. Thats what mine had anyways.
The drum brake valve sends only 30% to the rear and the disc sends 40%.
Here is a read up on it:
http://forums.beyond.ca/showthread/t-365650.html