Bed Height limit?

Hello. I am currently building my first lowrider 2. I am using 4x4s for the table with a sheet of 3/4 birch plywood across the top. I wanted the 4x4s for weight and stability. The bed sides would come out to 4.25", but the site documentation says 4" is ideal. Will I encounter any issues with this proposed setup? What am I not seeing? Thank you.

The bottom z brackets can (will?) protrude under the table so you are limited by the space between the bottom of the wheel to the top of the z-bracket.

Awesome, thank you for the photo! Appreciate the help.