Larboc mentioned in his 4300 project thread that his head gasket failed after rebuilding the engine. His head gasket was from an aftermarket rebuild kit. Where did you get your head gasket from?
It wasn't the head gaskets fault on mine. The JD part was identical to the maxiforce. It was a combination of two issues.
1) The block deck wasn't flat enough, the rebuilder didn't surface the block and the cylinders "liners" were low compared to the head bolt peninsulas. I redid it with the engine in the tractor with a big flat file.
2) Overadvanced SOI. My engine was billowing smoke and misfiring near wide open rpm. I now have no idea why it did this, possibly air in the line. At the time I thought it was injectors so I checked all of them with my homemade pop off tester but they seemed fine. I set the spillover fuel timing as outlined in the manual using the marks on the flywheel which required me turning the IP all the way to the stop. Smoke went away when I did this but noise went up. Headgasket failed about 5 hours later. After I did the new head gasket I put the IP back to where it was OEM and it never misfired again, blue smoke was much less than before. Looking back I should have known the noise was an indicator something was off but it had been so long since I'd heard it run I didn't remember what it sounded like!
I've seen diesels with blue smoke due to cam timing not being set right which is why I was so concerned about how those marks were aligned at the crank. I ended up pulling the front cover off just to check that I had done it right, pretty sure I did.
My suggestion, pull the head (must pull the fuel tank, uggh I know) and then surface the block with a good fine/dull flat file and continually check with a straight bar and feeler gauge till it's FLAT.
Put on a new head gasket and injector insulators (Cu washes will be fine to re-use but the insulators probably won't) and pop off test the injectors.
Did the engine seem louder after the rebuild? Does the rebuilder KNOW how they aligned the crank gear to the intermediate gear? Is the IP back where it was OEM?
Good luck. I've been EXACTLY where you are. Mine still smoked a little blue all summer until I changed the oil (deere break in oil for deere break in oil) and started working it harder moving sand and snow. Hasn't had any blue smoke since then but I've been working it harder. I tried to load it up as much as possible during the summer but the work I NEEDED to do didn't load it too much.
p.s. I outlined all of this in greater detail in my build thread.
