Since people have many definations of what a top or bottom overhaul is, so first we need to establish your defination.  What was the "top" overhaul for you, and what do you consider the "bottom?"

Let me see what I can find out for you.  You are going to take a hit though, since the cylinders and all will have to come off again, and labor will be significant.  As a rough guess, I would think you could figure at least $5000 for a new crank, bearings and labor.  I will check and see if I can get a better rough guess for you.  You also may need a new cam.  Can I ask for the details on why the engine didnt get a major overhaul, and what happened that got you to the point of a "top" overhaul?

Mike,
I did some checking around and think that you are probably looking around the $5000 (crank = $1000, cam = $800, bearings= $300 which gets you to $2100, I then guessed at the rest for labor and figured about 40 hours)(dont know if you got new rockers, pushrods ect.....) to do the job, provided you take it apart/reassemble and send it in for rework, and there is nothing major found.  Keep in mind that you will not have a good number until they check the runout and condition on the bench, so that number could vary substantially.  Dont know if you have considered upgrading your engine to a o-320, which I believe there is a STC for, and think you could find a good mid-time engine for the 7-8k range.  This would get you a little more horespower, and overhaul/parts would be a little less than your o-300.  With the o-300 not being as popular these days, parts are harder and more pricey to come by.  Let me know if I can do anything else for you.... This e-mail address is being protected from spambots. You need JavaScript enabled to view it