BAKER'S AUTO MACHINE LLC

I was not the one who took my core engine in to the shop.  My mechanic took it, believing he would get a better price than I would.  It took about two weeks or more from the time the engine was complete until the mechanic had it in and running.   From day one, the thing blew out clouds of blue smoke when I first started it.  Baker's said they would do that for a while after a rebuild.         
About 3 1/2 months after that, I was going to work when the engine temp gauge suddenly spiked, though there was no indication that the engine was hot.  I pulled off the freeway to the first station I could find and checked, but there was no indication the engine was overheating.  Verified there was sufficient coolant in the radiator and started the engine up...temp right in the middle.  Drove to work, and just as I got there, the spike again.  I parked and checked, but still not indication that the engine was overheating.      
Drove home and it did it again, but this time I ignored the gauge and drove home.  A short distance before my driveway, a loud knocking started.  Once I stopped the engine, it wouldn't restart.  Took it to a different mechanic, as my regular one was too busy.  He found that the head gasket had blown out, so that the exhaust gases were blowing into the cooling system, thus accounting for the spikes.  He said it looked like they had not used a quality gasket set and suggested I try to get Baker's to fix it or pay for the fix.   They wouldn't do either one, since it was 'out of warranty' and I was not the one who brought it to them. 
I ended up having a rebuilt head put on it, thinking the heat had warped the first one; and the thing ran, but had much less power than before and blew out huge clouds of blue smoke almost every time I had to sit and idle for more than a couple of seconds.  The mechanic replaced the piston rings and it seemed better for a couple of weeks, then the power loss and occasional blue smoke.  Took it to another mechanic, and they determined the cylinders are various degrees of OVAL, and they could tell it was likely that way since the rebuild; thus the reason for the blue smoke, I guess.  

Update: October 2013: I heard recently that a few years ago, the producers of engine lubrication products changed their formulations.  They removed, or cut way down, the zinc additives from them.  I don't know chemistry/metallurgy but was told that this causes premature wear in older engines, especially on fresh rebuilds.  This supposedly causes excessive/rapid wear on non-roller type lifters, and causes piston skirts to gouge into the cylinders until they are OVAL.  An engineer I work with has his older truck engine rebuilt, drove it less than thirty miles and had to have it towed home. He found that several of the lifters had been destroyed by excessive wear.  Well, I guess that's sorta what happened to mine.  I cannot verify that this is what the problem is, but firmly believe it to be the case.  I updated this review to increase the rating I gave the shop, which I did, and would have liked to give them a higher rating, but decided I shouldn't; only because I cannot verify that this is what happened; also because, if this is what happened, they should have given a much better notice to their customers of the need to use high-zinc-bearing oils/additives on rebuilt engines.