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Currently have a 422 SBC, 3.875 stroke, with a 900 base circle solid roller cam. The cam has been in the motor for 12 racing seasons now with .660 lift and 600 pounds of spring pressure over the nose, turning max of 75 to 7600 rpm with no issues. Motor is in shop for a rebuild and the owner of the shop does not like the cam, says they break a lot. What are other guys opinions and experience?
 

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I have a .900 base cam in my turbo motor, about the same spring pressure at .710 lift. Regularly spin it to 8200/8400, I don't like it either but it's been fine. As mentioned, if it's been 12 years your valvetrain must be happy.
 

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You could have it magnafluxed. For piece of mind.
But it'll probably run another 12 years w/o issue as long as you maintain the valvetrain.
 

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….. I have a 421 with a .900 BC cam and while it may not be ideal , its a necessity from a connecting rod to camshaft clearance standpoint … consider/measure that BEFORE you buy another cam .....
 

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Until I built the engine I have now, I've always ran cams with smaller base circles....Only way to get lift numbers past a certain point....no issues here with spring pressures 400 lbs on the seat and 1200+ open.....
 

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How many laps per year or can you estimate total laps? Cast core, billet core? Any valvetrain failures like broken pushrods or rockers at full song? All metal fatigues and breaks at some amount of "cycles". If it's got over million cycles on it, you've got a decision to make.
 

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Depends on the rods your using on my 421 builds I have been right at 1 inch with .420 lobe. Bot I also go with a .904 or .936 lifter to lower lifter pressure angle which is a big plus.
 

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If it's lasted 12 years, I wouldn't worry about it.
Unless the base circle is ground into the barrel of the cam core, the barrel diameter is the issue. If the barrel diameter is above .850", you shouldn't have an issue. There were some cam cores made, years ago with a .800" barrel diameter, and they were known to break.
 
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