if you want to swap bits from your cluster, with a caprice cluster, then you are going to be out of luck...
(been there, done that, and spent bucket loads of $$$$ trying to get a e3 grange cluster to physically fit my calais)...
Actually, none of the cluster parts are interchangeable (the cluster board, needles, face, screen and chassis are all different as the statesman / caprice cluster has its temp and fuel gauge elevated above the speedo / tacho. (they are also positioned further outward than the swb clusters).
If you want to fit the cluster, you will need the statesman / caprice crash pad, passenger airbag trim, silver trim spears, lower radio surround, and radio.....
It would only be worth while if you had access to a statesman / caprice wreck, and the amount of trim bits you would need to source would cost a lot of $$$$ of buying from holden.
Radio and cluster would also need programming, but in terms of wiring, everything should be there.
(if your ss is a series i, with a non lcd screen, you will also need to modify your hvac hce to fool the headunit in to thinking you have dual zone climate control)
i hope this helps.
(p.s. I have a brand spanking new e3 grange cluster if you still wanted to go ahead lol !)