John Deere 410 Backhoe
I have a new to me 1979 JD410. It was running well when my neighbor parked it about 10 years ago. I drained the fluids in preparation of trying to start it again and have hit a snag. I can't turn the engine over by hand. The starter was toast so can't try bumping it that way either.
Once I discovered it was seized I have:
Removed injectors and used 50/50 ATF a and acetone mix in each cylinder.
Removed valve cover to look for issues (didn't find anything it looks brand new in there)
No water in the oil.
Ran a Milwaukee m12 camera in the injector holes, inside cylinders were carboned but not unusually dirty, no rust.
Tried an impact on low setting on crank pulley bolt for some jarring action. No dice.
Loosened belt and turned fan and alternator by hand to confirm they weren't the culprit.
Disconnected the hydraulic pump so it's not holding me back.
Ratchet strapped the clutch pedal all the way down.
I have the reverser in neutral, hi/lo selector in neutral, gear shift out of gear too.
What else could be the issue here?
I have not pulled the head yet but may not have a choice.