I've been running an IDT Premier based 580" BBF with roller cam bearings for three years now as a street/strip deal including two Hot Rod Drag Weeks and any number of True Street drive to track, race drive home deals. I was worried initially about the cam bearings due to internet 'horror" stories. But they have fuctioned flawlessly. I also run a Peterson external pump set-up. First version of engine made 820 at the crank and a subsequent manifold change increased PMH by 5 so it gained, Valve springs are just shy of 300 on the seat and with 1.8 rockers there is a lot of pressure on the cam. I suspect I would have had cam beraing problems by now without the roller cam bearings. If you are at the aftermarket block phase then I would consider them essential.

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Bill Fowler
71 Mustang Convertable '03 Harley Davidson F-150