So I've run into an overheating issue. This happened two months ago, a thermostat cured it. I'm sure the whole system could use an overhaul. For all of the components in the system, are they a "universal" b series, or does it break down to specifics (i.e. b16, b18, b20)

I have a high comp b20b.

 

why not just have it flushed?

im sure the other components are fine.

if you are that worried change the water pump and have it flushed.

or flush it yourself

take thermostat out and bolt the pipe back up, then unhook the top hose and run water through the system backwards