Do you have a stock oil pump and have you seen a decrease in oil pressure on the guage? It may be nothing, but If I built an engine and found a worn part, I would change it out. Higher lift cams and spring pressures can make the shaft bend. I have had shafts break before. I try to stay with hardend shafts now. If it's thinner, it will flex more and can cause unstabil valve train problems. A mild build I dont see a problem tho. Do not over tq the hold down bolts tho. Disaster can and will bite you