So far just letting the frame protrude through the wood and making a sheet metal cover sounds like the suitable solution in this case.

Or is there something in the way of doing this, a cross member or something?
If it's purely an interference problem with the bed wood and the frame; the wood is easy to cut...

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
---All pictures---
"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-