On my '46 I took off the ribs above the gas tank and then used a '2" thick board in place and attached from the lip of the seat support. Used a 60/40 split bench seat from a 80s Ford ranger, split the board into two sections to match the 60/40 seat. Drilled holes that matched up with the Ford seat, attached with bolts from bottom side. Had to cut out a slot in the new wooden seat bottom and also flattened out the filler neck a bit to clear. let me know if you need more photos.

Look at my pics, you'll get an idea of how this worked out, best of luck

Last edited by JiMerit Boltr#43; 08/19/2021 11:02 PM.

It's easier to get forgiveness than permission!
1946 1/2-Ton Chevy
1953 Chevy 3/4-ton Factory Stakebed