40 Pickup Bedwood Question

[TomT/Williamsburg]

For the bedwood strips. I know I have to router out the board edges to sink the strips down but how much physical distance between the boards should there be? I am thinking 5/8-3/4” or just a bit more than the thickness of the bolt? I am using 1/4-20 2” hex head bolts with a washer to match the original clinch nuts and similar lag screws into the wood cross pieces.

I will only have 3 bed strips

Thanks for any help you can give ......