I'd assume you'd need the FSM for your roadmaster also.
Check in the roadmaster section and see if anyone has a FSM for your roadmaster & could possibly scan the pages you need.
or you can go to the donor roadmaster & start removing the plugs from there along with some wire and re-pinning the roadmaster plug with the caprice wires.
A good idea would be to sign up to various B-Body forums as the ISSF forum is a wee bit big and would be hard for anyone to see your post never mind answer it.
other forums are 4adrive.com, 9c1.net, naisso.net, inegma.net, 9c1.com, they can be of some more help as they are much smaller compared to ISSF.com and will have lesser posts and more replies.