2003 Gsxr 1000 advice needed.

I snapped my chain and I believe it has cracked the casing to the motor, this bike has 8300 miles and is very clean. I’m heartbroken do I scrap or do I replace with k4 motor and if so what year and price differences because if it cost near the same to rebuild the k3 then I’d rather have more power all together with a k4 motor