After getting an engine back together, it made it about 100 feet and overheated and seized. Is there any hope that it can be revived?

It's a Ford 300 (4.9L Inline 6). Do you think it's worth just pulling the head off and trying to free up the pistons? Since it heated up so quick would it stand to reason that it heated up in the piston area, and maybe it would only require a new piston? I appreciate any help/well wishes.

Added (1). Thank you everyone for the responses. I pulled the head off and it looks like one of the pistons is cracked and the connecting rod to that piston broke at the crankshaft. The rest of the engine rotates just fine without that piston in there. Looks like I'll replace that piston and try to figure out what went wrong.

That's too bad and very hard to say. We don't know why it seized or at what rpm. There may have been oil starvation and galling of the bearings. Pushrods may have been bent. Cylinder walls may have been scored. The pistons could have irreparably been damaged. There could be metal fragments in the oil pump and in the oil galleries. You screwed up big time once so don't take any chances of spending more money only to screw up worse. A complete teardown and inspection is called for but if you think you can get lucky… Go for it. You'll learn soon enough.

You may as well disassemble it and see if there's any damage. Obviously it was not set up correctly. Check all clearances. Any attempts to get it to run will make it worse. Check your ring gaps.

Once it cools down it may free itself off. Put some oil in it and/or clean the pick up strainer in the sump.

Did you put oil and coolant in the engine before starting it? If not, the bearings are gone and just pulling the head off isn't going to help.

Always! How long was it running b4 you drove it 100 ft?

I suspect you had an oiling problem. Possibly a wrong gasket that plugged a crucial gallery but an engine doesn't over-heat in 100 feet.

I found your question after your update was added, so I see what you found.

I'm sorry that you had problems, but based on how you describe everything, I think that you are trying to do things that are way beyond your knowledge and capability.

Removing the engine (yes, OUT of the vehicle) and TOTALLY disassembling it is the next step. Not trying to stick a replacement piston and rod back in and keep going.

You must first determine of the engine block is usable. It may be damaged beyond repair.

Next, you need that crankshaft out of the engine and inspected.

Then you'll have an idea if it's salvageable.

Sounds like you ran it with oil starvation. Did your startup of the newly reassembled engine involve a new (empty) oil filter?

How long did it run before the damage happened?

Was there loud knocking?

Or maybe you had open exhaust?

Take the bare block with main caps and crankshaft to a competent automotive machine shop for an initial inspection.

I found your question after your update was added, so I see what you found.

I'm sorry that you had problems, but based on how you describe everything, I think that you are trying to do things that are way beyond your knowledge and capability.

Removing the engine (yes, OUT of the vehicle) and TOTALLY disassembling it is the next step. Not trying to stick a replacement piston and rod back in and keep going.

You must first determine of the engine block is usable. It may be damaged beyond repair.

Next, you need that crankshaft out of the engine and inspected.

Then you'll have an idea if it's salvageable.

Sounds like you ran it with oil starvation. Did your startup of the newly reassembled engine involve a new (empty) oil filter?

How long did it run before the damage happened?

Was there loud knocking?

Or maybe you had open exhaust?

Take the bare block with main caps and crankshaft to a competent automotive machine shop for an initial inspection.