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Why steel pushrods? Some say they are noisier, Gene Berg says they are not.  No valve lash, they must weigh more than aluminum, stronger, less flex? Only to be used with high lift rockers?  Please advise. I’m curious and this has nothing to do with engines built by me or for me by anyone past or present.

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Chrome moly (steel) pushrods are stronger than stock aluminum rods. They grow less than aluminum, so the valve lash sets differently. With aluminum, valve lash is set to .006 cold, and tightens to .002 or less when warm. For chrome moly, set at zero, and they loosen to .002 or more when warm. Chrome moly rods have a distinctive clatter when warm, and the engine tends to run rough for the first 30 seconds or so when first started, until the cylinders, heads, and pushrods grow enough to counter the quicker initial growth of the exhaust valve stems. Stock aluminum pushrods will bend or mushroom if used with high tension single or dual valve springs. Chrome moly can handle the extra stress. There's also a tapered aluminum pushrod available, that can handle high tension single and dual valve springs. Best of both worlds, strong and quiet. 

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