There are no replaceable cam bearings on a 22RE. The cam rides in the head in bores that are machined right into the head. Most likely they are OK. If not you'll need a new head.

One vendor of timing chain kits who used to be on this board a lot talked about the necessity to be very careful to torque the timing chain tensioner bolts to spec. Early failure being the result if the torque wasn't right. -- Matt

'89 4runner SR5, 3.0, auto (fun)
'93 xtra cab, dlx,3.0, 5spd (work truck)