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Cracked block - What to do ?


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Working on restoring my 1974 Datsun 620. I pulled the oil drain plug and about a pint of anti-freeze coolant ran out followed by some nasty, brown colored oil.


Next step: I blocked off the lower block return, then pulled out the thermostat and filled the opening with about a gallon of 50/50 anti-freeze.


There now is a very slow dripping of anti-freeze comming out of the oil drain. It appears that it has a cracked block. The truck was parked outside for several years and I would guess it contained coolant not mixed strong enough for our cold winters. The freeze plugs seem to be intact.


Question: What the hell do I do now?? Any repair possible? Or is it toast. Your comments please.

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Or leave the pan on. Listen with a hose while pressuring the system.


Is air leaking sounding loudest?

* Through oil fill hole? If not, no need to pull the oil pan.

* Through carburetor? Leak is perhaps in intake manifold, intake gasket or cylinder head

* Through exhaust pipe? Leak is perhaps in exhaust gasket or cylinder head

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