Very few camshafts have been replaced however GM in their ways to save money will want to replace just the bad knowing very well that the others will have to be replaced in the future. Be relentless in your push to get GM to pay for this repair as they know its a problem. Dont know what the smog laws are for your state but a DFM tuner might violate them.
You mentioned that you used seaform so I thought this video might interest you.
