Wrench87-
The only cam core that a stock type cast dist. gear can be used on is a stock type cast flat tappet cam. Any of the billet cam cores will require a bronze (old school) or a composite (new school) gear. This is regardless of the lifter type. Most of my experience is with small blocks, but in my recent Fe Cobra build, I used a billet camshaft. My friends at Comp informed me that the composite gear for the Fe and 351C, same gear, was not available yet. So I used an old bronze gear for the 351C that had the same ID as my new Fe dist.
What I did do was grind a small slot into the block behind the front cam bearing pointed in the direction of the dist. gear. Mind you, a very small slot. This will shoot a constant stream of
oil onto the dist. gear for cooling and lubrication.
Distributor gears can wear very quickly and will generally only last a few minutes when incompatable parts are used and
oil pressures have been altered.