The 'burb tank will hang down pretty low and be visible fromt he back of the truck. Some folks don't like that. If you don't like that look you can do a custom installation like I did.
See posts no. 8 & 29 in my build thread
http://67-72chevytrucks.com/vboard/s...d.php?t=363509
First photo below is the 49 chevy passenger style fuel tank,
2nd photo is a Suburban style fuel tank
3rd photo is my truck with roll pan installed, tank can't be seen from rear.