351M Busted Cam?

[OFOF]

One of my offspring (Ted) who lives in Kingman, AZ has an old beater 4X4 Ford truck that he just loves to try and kill on hills, mud puddles, etc.  Recently, on a trip home from Phoenix, he lost some power while cruising down the freeway.  After a bunch of analysis and false starts he found the #4 and #8 rockers were not moving when the engine was running.  Has anyone had any experience with the cam breaking on one of these 351M engines?  I can't figure what else it could be other than the cam.  Any ideas? Suggestions?
Don.

[enjenjo]

Not specificaly on 351's, but I have seen Ford break cams.

[DRD57]

I had that happen to a 440 MoPar. Since the dizzy is in the front it still ran. Haven't bought another Sig Erson product since.

[Jbird]

I had a customer with a 400M in a Galaxie with the same problem. He drove it for a couple of months as a six cylinder before he brought to me to fix.
The cam broke for no apparent reason.      Jbird

[junkyardjeff]

I had a 78 F150 that had a 351-M and the cam broke on the previous owner,it had a RV cam in it when I got it.  Jeff