New lifters on a used cam

Back in my dealer shop days we installed hundreds of new lifters on old cams under warranty... never had to worry about a break-in time because those stock springs didn't have much pressure and the customer would never pay attention anyway.

I remember when the dealers always told a new car customer never to drive over 60 mph for the first 100 miles... old school way of breaking in a new car. That didn't take into account the new car set-up guy (me!) going 120 mph on the 'test drive'! I broke in hundreds of Hemi's, 383's, 340's, six-packs, etc that way...