You might try to find a Russian M-14 or its predecessor, the AI-14. They're fairly inexpensive in the US. I found one "firewall forward"--included the prop, governor, mags, etc. for sale for $12,500 (US) in "good" condition, no logs. If you found a run-out engine in Eastern Europe, it could be a steal!
I've flown behind this engine in a couple of airframes and it is a beast!