the answer to why can't a large journal cam have the bearings ground down is easy, the journals were larger to allow a larger base circle for the lobes, and the last lobe doesn't fit through the second to last bearing, necessitating a regrind. At least that is what happened to me. I had the journals on my brand new cam from howard cams ground to the smaller dimension, when it didn't fit, I sent it to delta cam to regrind, and they lost it and gave me a GMC cam, I eventually ended up with an old regrind that had at least been reground twice. I had $300 dollars into that old wore out cam before it was all said and done... That is why.
