If he has an after-market cam, especially an overseas one, the cam gear may be ground off-pitch or hardened incorrectly. The cam bearings/saddles could be loose or bent cam, causing wobble. Head could be warped and saddles not aligned any more, so cam runs slightly down-hill or up-hill at the cam snoot. Never seen this on a Toyota before, but have on USA engines. Turn engine over (not running)and check run-out of the cam in several places and plastigage the cam bearings/saddles, top, sides, and bottom. Good luck.
