For a factory
1964 Chrysler 300K with the 413 cubic-inch "Wedge" engine, the standard camshaft base circle diameter is approximately
1.164 inches (or roughly 29.5 mm). [
1]
This specification is shared across most big-block Chrysler "B" and "RB" wedge engines of that era. Knowing this measurement is critical for calculating lobe lift and ensuring your pushrod length is correct if you are moving to an aftermarket grind.
Allan Pozdol