cam break-in PROBLEMS

[Murray]

I put a 351W into my '68. It had 15000 miles since a rebuild when I got it. I installed an Edelbrock Performer cam, timing chain and gears and a Performer intake. This morning was the 30 min. initial start up to break in the cam. I turned it over first to build up some oil pressure. I started it on high idle and she purred like a kitten. About the 5 min. mark I heard a couple of random clunks and it began to run a little rougher. There was a few more random clunks and a couple of slightly louder ones at the 15 min. mark when I shut it down. Did a break a lobe? I followed Edelbrocks instructions to a tee. What should I do now (besides go for a beer)? Murray