You won't find hole dimensions for a '48 frame in the FAM, as everything there is later.
Probably the only way to get the actual dimensions is for a fellow 'bolter to measure their '48 frame.
Or you could locate the tank where it fits and drill holes appropriately. You just need clearance from the running gear.
The tubular shocks started in '50, so your frame is '50 or later.
This all assumes it's a 1/2 ton (3100) pickup. If it's a heavier truck, it might have had a frame mounted tank and there might be the appropriate diagram in the FAM, but I don't recall seeing hole locations in the frame sheets.
Last edited by klhansen; Mon Dec 09 2019 06:41 PM.
First car '29 Ford Special Coupe
#2 - '29 Ford pickup restored from the ground up.
Newest Project - 51 Chevy 3100 work truck. Photos
Busting rust since the mid-60's