Long story short: My G63B overheated twice because of a cooling system leak and I'm sure the head is warped. I found a professionally rebuilt 4G52 locally, most likely without the MCA jet head. It's narrow block and I have a KM132.

Would it fit into my truck? Is the 4G52 a step backwards in terms of performance or reliability compared to the G63B? What about the clutch and flywheel?

Is this a bad idea?