[Gaz64]

I've seen many roller lifters have needle bearing failure, hence why some manufacturers make bushed lifters, more bearing surface area.

If the bearing starts to overheat/seize, then the roller skids on the cam lobe, then it's all over.

Strange for 2 for have total failure like that.

I wouldn't use any factory type gear (Ford or GM) in a high power combination.

There are way better "tiebar" configurations available.