Stepside cross sills and bed strip hole dimensions

[69HopeTruck]

Hello everyone
First post for me!

I bought this brand new bed over 14 years ago and just getting around to assembly. (Don't ask, wife, kids, moved 3 times 3 states..... You get the picture). Truck is a 69 stepside.

My problem is there are no holes drilled in the sills or bed strips. Can anyone provide the dimensions? See pictures and let me know if you have any ?????,s

Contacted manufacture of bed and mar-k with no success of getting these dimensions

Thanks