If you don't mind it being custom, check out Tanks, or go to the junkyard with a tape measure. An S-10 tank might fit where you describe.
The vendor you talked to is incorrect. The 47-48 trucks apparently had the tank mounted on the frame, but in 49 changed to have it behind the seat.
Last edited by 46gmcpu; 08/02/2013 9:56 AM.
