I am currently getting ready to swap a 307 old to a GM Performance ZZ4 350 (turn-key) in my Caprice. I know that I need new motor mounts, radiator hoses, TV cable bracket, headers and exhaust, more money...
The 200-4R has a dual bolt pattern and I have dual batteries, so the starter being on the other side is not a problem.
Is there anything else I am missing? or should i say how much am i missing  

You will need new frame brackets for the motor mounts to bolt too.  I forget the exact year of your Caprice, but find a similar/same year and body style car at the junkyard that had a chevy small block engine and take the metal frame mounts.  You can probably order them somewhere online as well.  Wiring issues for accessories in different places, such as the oil sending unit on the  olds is on the top front of the engine, Chevy's on the bottom rear. If I remember right the alternator's were opposite (olds on the driver side, chevy on the passenger) as well as the A/C system if your's works.  Fuel feed line into the Q-jet goes from the front to the side on Chevy's, unless your Old's Q-jet bolts on properly to the new intake (not sure on that one).  Fuel Pumps in the same place so that's good. Torque Converter should bolt right to the new flex plate (match the starter to the flexplate)

Outside of the frame mounts all the other things I can think of are pretty small details.  That's all I can think of.