How to match preamp and power amp?

How to match them by looking at the preamp output impedance and the input impedance of the amp? Any magic numbers? I don't understand their relationship. Please help.
Would I be correct to assume that most SS pre-amps would work well?

Nearly all preamps, whether tube-based or solid state, will have no problem driving 100K. And that would certainly apply to a solid state preamp having an output impedance as low as 160 ohms.

Regarding the sensitivity, the 2.71 volt figure most likely means 1.35 volts per leg (i.e., for each signal in the balanced signal pair), which is about average.

-- Al
My Cary SLP98P is 800 ohms impedance output, the Pass Aleph 2 has 10 kohms input impedance, will this work. It’s seems so from what I have read?,  But there are more knowledgeable folks on this forum who can advise? 
I was considering a 4m run of Nordost Red Dawn RCA unbalanced interconnects, does this effect the equation? 
How to match preamp and power amp?
To determin "if" you need passive preamp (no gain) or an active preamp (with gain). There was a test that was a very good indicator, and that was the "Revels’ Bolero Test". This cd starts off extremely quite for quite a while and builds slowly.

You do a direct connection between source and poweramp (no preamp) making sure if it has it the source’s volume is up full.
Switch everything on and press play to start "Revel’s Bolero" just for safety have your finger ready on the source’s stop button if it gets too loud as it get’s into it.

If it get too loud or is way over your normal listening level, then a 10kohm passive preamp will do you fine, like the $49 Schiit Sys. If your poweramp has 33kohm or higher input impedance.

If the sound is not loud enough even over 10mins into "Revels Bolero" then you need a preamp with gain, a Schiit Saga or Freya are great buys also, these can also be passive as well as active

Cheers George
@RPNZ: Cary Audio's published specifications for the the SLP98 show the output impedance at 440 Ohms, not 800.  Yes, I know this is an old thread.
Ok - So I have a Copland CTA301
    Output load 2. 8kohm
     Output voltage (at the time of 47kohm load) Rating: 2V Maximum: 50V
 And Caspian M2
   Input Impedance 38 kohms
    Input Sensitivity 240 mV rms

Would that work?