One thing that hasn't changed in roller camshaft technology is the distributor drive gear. You want to make sure you get an iron gear, which will happily mesh with a standard distributor gear. Since roller camshafts come from a race lineage, most aftermarket roller cams will require that you install a sacrificial bronze distributor gear if you don't specify an iron gear. The bronze gear on the distributor is softer than the camshaft so that it wears instead of the cam gear. This means one more thing to inspect and periodically replace if you don't have an iron gear on the cam.