Aluminum Push Rods

[70Turbobug]

With cylinders,case and heads made of aluminum the expansion of the components are identical. All aluminum no matter what alloy expands and contracts at the same rate. As does steel and iron at the same rate. Aluminum expands greater than steel/iron. So with aluminum pushrods you can actually run a tighter valve lash clearance if the rest is also aluminum. With steel/iron cylinders you need more clearance because the aluminum expands greater and faster.

-Mark