You can find a 0235 C series engine core for 1500-3000. With a premo
overhaul including new Lycoming cylinders and Cam you will have less
than 15K maybe 12-13K and have for all practical purposes a "New"
engine good for 2400 hours TBO. I have such a engine in my RV3 that
was overhauled like I just described to use in my Colt about 400 hours
ago. The only cooling problem I have with my installation is the oil
temp is hard to get up enough to boil off the moisture from the engine.
I have yet to see more than 180 degrees with the oil cooler blocked off.