whats the oil that i should run

hay guys wondering what oil everyone is running and why. I have a 340 with hyd flat tappet cam I heard of people running standard oil with an additive added to it but I don't want to do that I currently running joe gibbs hr oil conventional oil here is my problem a friend of mine is also running joe gibbs in two gm ls cars one 700 plus horse power and the other 1200hp and now has bearing failure and it got me thinking is it the oil or is it just his cars he is running the synthetic stuff but they were together for a while need help should I drain it and go with something else