I need help

I have tore down 3 6.5 looking for a good crankshaft and everyone of them
has a crankshaft that has at least 1 badly scored jornel and 2 bad rods. Can anyone tell me what causes this and how to prevent this problem once I get to build my engine
does it need larger oiling holes in the crank? is there a restretion some where in the oiling system? I sent my block to a local machine shop to have it hot tanked and checked for cracks the machine shop bored my block 40 over said it was done all the time?? and I will have no problems ? I still wondering about that

 

Sounds like you are finding ones people ran out of oil. Don't drill the crank any. Infact if you have the money I would replace it with a scat crank. Usually they will just break the crank.

 

scat cranks are pretty cheap and are better than the stock ones so i would go with that