Interesting stuff Spook. It looks like a good selection of parts, just badly put together.
The NASCAR boys are restricted to 358 cubes with a 4.185" max bore. That means a 3.253" stroke. They pull 10,000 RPM all day with the shorter stroke.
I've read about changing to 302 mains on 351 motors. The standard 351W has big main journals which makes for a strong crank but they don't survive when reving hard.
The reason is
oil shear. When the crank rotates in it's journal there is a film of
oil in there keeping the two surfaces apart. Under extreme mechanical strain the
oil will lose it's viscosity and cease to keep those surfaces apart. The larger journal means the oil is having to travel faster for the RPM's the motor is running. Switching to a smaller journal slows the oil movement and lets the motor rev harder before the oil loses viscosity.
I believe this is one of the reasons why the 351C motor was a better rever than the 351W because it has smaller main journals (and fricken huge ports).