Im making progress on my F 600 4 x 4 firetruck restoration
and I have some fuel tank questions

I would like to put a tank over the rear axle along with a second tank. The axle tank has a location area of 28" wide (frame width) to about 30 plus inches long. My primary question is what size are the factory light duty tanks ( and frame rail width) and would they possibly fit in this area. Im thinking of a new poly tank (truck will be a NAVSTAR diesel)...

I most likely dont have room for inside the frame saddle tanks because of air tanks etc taking up those spaces

Any suggestions?

On the second tank I have several options... my parts truck has a like new behind the seat tank.. it would require retrofitting it to my non tank cab.. do-able but a pain in the butt... and I would lose behind the seat storage.. which might be nice to have..

I also have a set of saddle tanks off an f650 uhaul truck.. with built in steps.. but they hang down pretty low for a 4 x 4 if I used them under the cab.. behind the cab they would tuck up nicely

I can custom fab a tank.. but I would rather go with a new poly or steel one and be done with it

I have several late 80/90s Ford f250 diesel parts trucks with like new tanks but unfortunately they are way too wide


I appreciate any help in tank sizes from the lighter duty trucks

notme