Flat tappet cam lobes are ground with a slight angle to them so the contact with the lifters will push the camshaft to the rear of the engine to prevent the camshaft from walking. I've read a fair amount recently where a billet steel cam gear will cause excessive wear on the front of the block. All the accounts I've read about involved both small and big block chevys. Some are recommending a thrust washer, others a torrington thrust bearing, and still others a cast cam gear. Any one of the three is supposed to fix the problem. Could it be another area affected by the reduction in Zinc?
John
