I have a freshly rebiult 396 (4.040" bore x 3.875" stroke) with about a 1,000 miles on it. I had a leaky head gasket so I pulled the head. My engine is already starting to show wear in the cylinder bores. The cross-hatching (sp?) has worn away in about a 3/4" wide strip on the upper and lower portion of the bore...from side loading? The pistons are new custom slugs from Diamond and I run a 6" rod. Seems like I should not be seeing this much wear yet so soon. I'm running dyno oil as I'm still breaking it in 5w30. Has anyone else had this experience? Any thoughts appreciated...

 

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