Small Engines (Lawn Mowers, etc.): toro snowblower 8hp, piston movement, stranger things

Question
I removed plug, no movement to piston. I didn't remove shield to check pulley. Is it possible to have both parts broken? What options do I have ? How hard is it to replace the complete engine vs rebuilding the short block? Thank you-------------------------
Followup To
Question -
while clearing the driveway,the blower made a loud clunk and stopped. I didn't hit anything, it just stopped.Tried to start it with rope pull but engine just spun freely.The rope would retract okay but it sounded like something inside the engine was just spinning.  It's a toro model 824. Bought it new in 1987. HELP !!!!
Answer -
I would start by removing the spark plug and checking for any piston movement.  If there is no movement, the connecting rod likely broke.  If there is movement, remove the shield that covers the drive belt(s) and observe the pulley as you crank the engine over.  If there is no movement, the crankshaft may have broken.  Once you narrow down where the problem is, let me know and I can help you with the repair options.  Hope this helps.

Answer
It's unlikely that both parts are broken but stranger things have happened.  I would say that if it just the rod broken, a thorough examination needs to be done and if all the engine needs is the rod replaced, that's the way to go.  If other damage has resulted, a short block would be better.  As for degree of difficulty, both repair routes require removal of the engine and are both require about the same amount of time.   You may also want to search for a good used engine that will bolt right on.  Hope this helps.