I just found a crack in my block when we started to clean it up to reassemble. What do I do? Are there any options, or is replacement the only way to go? This sucks bc I just had the crank polished and it is perfect. New bearings are in and I was ready to put it back together. Not sure which position this is called but it is in the middle and closer to the back of the motor if that helps. Thanks

Someone send me a good block please and could you get it here overnight. 
nothing has gone right with the "resealing" of the motor. it was running well before I touched it. 