Are you selling or buying? I would want to remove the heads to check for cylinder to valve cracks before making any offers if I was buying. I would not pay for one that I couldn't inspect.
I don't think there is a "going rate". I think you have to "shop till you drop" to find one in reasonable condition, a reasonable distance from your home base, at a price you can afford and the seller is willing to accept. I've seen "complete not seized" go for free (zero dollar$). What about the rest of the condition? Of course, people on forums will tell you otherwise. $100, $300, $500 whatever comes to mind, but I still say there is no "going rate".
For one you know nothing about internal condition wise Ive gotten them for Free-the $50-$100 range depending on what was there that I could physically see and assess. The more you know and can physically see the more the price will go up. Just because it turns over doesnt necessarily make it a "good" block. But... Just because its cracked doesnt make it a "bad" block either. Just means more $$$$ to fix it. There really is no going rate. How bad do you want it, and how bad does the seller want it gone?...
I bought a fully rebuilt Merc Flathead with Offy heads, Mallory Ignition and Offy 4 barrel intake with a C4 transmission for $1100. That was a couple of years ago.
I paid $400 for a complete, good running '51 Merc engine. But it was 20 years ago. I was, (and still am) happy to have it. That should tell you something.
I paid $300 to have an engine delivered sight unseen in a snow storm, because I needed any flathead for mock up. The engine was a stock looking 59 model. Turns out its .30 over with adjustable lifters and aluminium cam gear. Block was good but I already had a motor being built. The builder traded me an empty block, in turn for what I found he did a balance job on my engine. The gears were also good so I dropped them into a top loader and sold that box off. I have also paid both $100 and $200 for a motor that was no good, one was a 1936 with a 97 on it. That being said I would not pay more then $400 for any running motor with signs of age. Don't care if you drove it onto the trailer when you bought it, you never know what your getting into till you open it up.
I just sold a 1951 year Merc 4 inch stroke crank rods and mains 010 For 400 dollar's and the buyer told me I sold it to cheap. Years ago I got them free to 100 dollars for stock ones. In the last 10 years I have paid 200 to 700 for running stock engines..
The Jalopy Journal
