Since a few years flat tappet failures have been going up. There are several factors involved (new aggressive lobes, oil formulation etc.) and one of them is the quality of the cam core. Which companies are still making flat tappet cam cores? Which cam grinder uses which company? Or do Comp Cams, Lunati, Bullet, Mike Jones all use the same cores?
Is there a reason why choosing one cam core over the other?

Thanks