Hidiy Judson-
That's a "buyer beware" situation (meaning you), but you should at least make sure the engine will turn over. Look for obvious cracks on the head & maybe see if you can peek under the valve cover. Print off the shop manual engine diagram page or a picture of a complete 235 engine to compare to the one you're looking at purchasing. Make sure all the parts are there.

Another concern is that whoever is selling it may not even know what condition it is in. If the previous owner had it rebuilt, I'd ask for any paperwork/receipts they may have for the parts, or at least ask who did the rebuilding. Ask tactfully, but a "no" answer to that information would be fishy to me.

You don't have to post it, but their asking price will be directly proportional to how much the 'rebuild' parts cost if it was a recent job. New parts for a complete rebuild of a 235 are about $700-$900 (at MINIMUM).

Hope this'll at least get you some thinking points & I hope it works out for you getting a new motor.

Brad

Wrench Fetcher, PhD