Motor advise for U20

[Clearview12]

Been driving my 69 2000 since 71, replaced new motor 95. Recently dropped valve seat and had machine shop replace and valve job. Assembled motor and leaking coolant probably from head. Is there anybody on east coast who can replace motor

[spl310]

Where is the coolant leak? Where are you located?

[sfdaugherty]

It is very common to have coolant leaks (especially from a U20) from the manifold gasket. I've had to go back and use a good sealant around the coolant passages to stop leaks. It may not be a bad engine.

Shannon

[notoptoy]

Where are you located on the east coast?

[DLR25]

Tighten the front and back header nuts at the header 90. The stud/nut are very close to the bend in the header. The intake/exhaust gasket seals 2 coolant openings in the head. That is causing the leak. You'll likely need to remove the windshield washer tank to get your arm between the header and block to tighten these nuts. The nut is either a M12 or M14.

[Gregs672000]

What DLR25 said... (welcome BTW). It's likely that there's nothing majorly wrong. Was the engine over heated at some point and that's what led to the seat drop? Was the head surfaced or cut? It's probably the manifold gasket as suggested.