PRC duals .650 lift. That's the first I've ever heard that. I let the motor idle for a least thirty minutes at one part not the. It had 400 miles put o. This motor including g the tuning for it.

 

That is for flat tappet cams not hyd roller cams. Roller cams don't need a break in but still not a bad idea to run at 2-2500 rpm for 10-15 min to get oil up on the rollers. Also can't go wrong with the zink. If roller cam takes a the core is too soft, spring too stiff, or lifter took a . The stiff dual springs are usually the cause of premature cam, and lifter ware. Once you get past about 330 lbs open pressure on a daily driver reliability is greatly reduced.

 

i feel like what you ^^^ said is what happened to my motor im thinking about just doing a single valve spring like the pac 1519's.

 

My buddy just bought a comp cam for his Yukon and that's what it said for break in. The guy I bought my cam through doesn't even use comp any more because he got tired of his costumers having lobe whipping issues. Soon as I seem mine I made phones calls and that's what he told me. I was running patriot performance duals. My stock lifters didn't have this issue and neither of my stock cams had this issue. These were new lifters rods and cam when it was all installed. Actually I think the lifters had a few miles but not many.

Only reason I replaced my lifters was because I thought they weren't pumping up. Turned out to be a damn crack in my manifold.