I am repairing a 41 Oliver 70 for a friend. We have a cracked block, cracked between 4&amp;5&amp;6. The head gasket looks OK the head looks OK. Now we need a used block or engine. My s/n is 238457 the casting number on the block is D600A330. Need help finding parts. Thanks in advance. Tim Rees Omaha NE 402-679-5819