Jacko, the easiest way I can think of to tell them apart is to see if there is an intercooler on the engine. The 9230 would have one, a 2166 would not. Also look at the serial n tag on the front cover by the injection pump, somewhere it should say "Engine model" or something close to that. If it says "6T-830", it would probably be one for a 2166, if it says "6TA-830", it would indicate it is aftercooled and perhaps out of a 9230. The injection pump would be different between these engines, the turbocharger is "mounted backwards" on a combine, meaning the air intake side of the turbo faces the rear of the engine, whereas on a 4WD it faces the front of the engine. As far as engine HP, a 9230 is rated at 235HP, while the 2166 is rated at 215, so its not a lot bigger HP-wise. Good luck and HTH.