Funny thing is, I had a post this A.M. in this thread, asking the same exact thing about hooking up the rb alt.
I wasn't 100% sure what to do with the T plug thats on the Z harness for the alt. I ended up splicing the brown plug off the rb lower harness onto my Z harness.
I had so much junk stuff I deleted from the Z engine bay (shunt, voltage reg, seatbelt interlock, etc.) which left plenty of un used plugs and connectors hanging....
I just hooked up the rb alt using the Z harnesses connections, and the starter the same way. I hope to get power to the starter/ alt. just like if it were the Z parts.
Since I'm using a Tec2 standalone ign, and all new electrical AutoMeter gauges, I should not have to much trouble getting the starter and the alt to work. The rest is all new rewire anyways. I'm soooo close to starting her up....