Jimmy,
The difference in the PS on the RMW vs Caprice is a sensor on the steering shaft outside of the firewall and an extension on the back of the PS pump. Yours should have the variable assist and have the extension.
IMPORTANT: When you remove the old pump be sure to keep the extension and/or the valve that screws in the back of the old pump, they typically do not come with replacement pumps.
Identifying this is easy. If your steering pressure line comes out toward the fender well you have the variable assist. If it comes in from the rear of the pump (firewall side) like my Impala then it does not have that on it.
BTW the 9C1 style lines with a cooler built in are available for both options if that is something you might replace.
Hope this helps!