The stock drive shaft in an oil pump is more likely to fail when it is subjected to the stresses of non-stock usage, such as high volume oil systems, heavy racing oil, and high RPM applications Failure could be catastrophic to your engine, so upgrading to a Milodon performance oil pump drive shaft could be good insurance at a low cost It is cNc machined from 4130 chrome moly, centerless ground to avoid stress risers, and features induction heat-treated ends to reduce wear