Breaking in the cam running on just the outer spings is a precaution you can take but IMHO, with 995 springs or similar, a waste of time. The shop that I use for machine work (and parts) never breaks in a cam with the outers only if they are low pressure like the 995s! They have built many many engines in the last 35 years and their failure rate (from what they told me) is very low like they lost a couple out of a thousand. IF you were to run very high spring pressures, way more than 995s then it would be advisable (again, as I was told). I have broken in a lot of cams over the last 30 years and only recently experienced failure. The last cam was a Crower that is fine but the two prior to that were a Comp XE and a UltraDyne that failed. The Ultradyne seemed to break in fine (it was a solid and the lash did not open up) but by after 60 miles of use the lash opened up .006" on 14 valves. Inspection of the cam revealed porous, rough looking lobes and I had a small amount of iron filings in the filter. It was sent back to Harold and he is taking care of it. I don't know why it was starting to "go".
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