Builders: Square engine, Over Square, or Under Square for you?

A normally aspirated engine will always prefer a bigger bore to allow larger valves to move more air.

Higher rpm racing engine you would want way over square 4.375" bore x 3.91" stroke. Heads up you're going to need it still pulling at 7500 rpms without running out of head.

Depending on the level of truck pulling I would use 4.375" bore and a 4.25" stroke. I've sold several 3.91" stroke cranks to pullers that are cubic inch limited.

Family car probably never sees 4000 rpm. 4.375" bore x 4.25" stroke. Let's make that old land yacht eat rubber for a city block.

Tom