I think that there is a hole in the cam bearing that is used for this purpose. I don't believe a pin is used. A punch is used to stake the bearing through the hole. I believe there is an illustration in the manual.
I hope that someone can comment on this further because this is a very important step.
Yup, truckernix is right, I just checked my manual and it's like he says. The manual shows a "Tool #7 (staking tool) for the job. Manual says to "mark the face of the cam bearing bores so that you have alignment for the oil holes, then press the bearings in and stake them in the hole provided". You can probably substitute a long 1/8" punch or center punch and just dimple the bearing into the hole provided.
My only experience with staking cam bearings is with F**d tractors. Sorry about the misinformation.
Fred