Thanks for the reply and the advice. Is it possable to do it in frame?
Maybe. Possible or not depends on why it's stuck. I don't know the 480 specifically, but with most engines you can pull the head and pan in the frame to see what you have. If I was young again that's what I'd do.....basically figuring maybe I'll get get lucky and can fix it in the frame for the cost of rings and gaskets. If you do have to pull the engine, having the head off gives you convenient mounting points for a chain hoist.
On the other hand, I'm NOT young again and hate working laying on my back.... nowadays I'd probably do as DJ54 recommends. But I've done it the other way successfully. Just not on a Case 480.
BTW, those are nice tractors. I still see them in service - especially at local sand and gravel construction sites. 4 speed with reverser, powerful loader,big 3pt, and PS. What's not to like?
Oh, and another thing. Before you start in pulling the head and pan, make **** sure that it isn't the clutch or starter that is bound up instead of some internal engine part. You'd feel real dumb if you pulled a good engine apart and found that it was fine but couldn't turn because of some peripheral component. I've even seen tractors coming from flood areas that have the the clutch housing filled with mud and then rusting solid enough to make you think the engine is stuck.
A starter can lock up an engine if the starter gear is locked to the flywheel ring gear. If you simply take the starter off, that will eliminate that possibility. You probably want to rebuild the starter anyway.
Everytime you take something off, put a socket and cheater bar on the cranknut and see if you can turn it.
I imagine you have already done that, and maybe pulled the injectors to pour in oil as well..... ?
rScotty