OK, we took the motor apart yesterday and found a small 1 1/2 inch long hairline crack under where the intake sits. Just to the left center. This motor has sat up for about 1 1/2 years. The freeze plugs were blown out. I was told that the spot can be welded, is that true? Everything else on the motor is fine, no other cracks and it was rebuilt 6 years ago. Very little wear on the parts. Is it worth fixing?

 

Welding on cast iron (especially cracks) is very hard to do. Cast iron has very poor weldability at room temp. The only way to effectively weld a crack in cast iron is to find a place that will heat the entire block up to a few hundred degrees drill out the ends of the crack to keep it from propegating further and weld it. then the entire block must be cooled slowly to prevent any additonal stresses from forming. Generally not an easy task.

 

Unless its a 4 bolt main block, dump it and get a D1VE block froma wrecking yard. They are common and are a good block. Get it magnafluxed and its tolerances checked, machine as nescessary.
Tony

'77 F250, 4X4 460 transplantee, "Flamer"
'74 F250. 460, "beater" now "1 dead ford"
'73 F250, "midnight auto" now a trailer for the flamer

 

Not worth it. Get a new one.