What happened to your 48 tank? 47 and 48 were the two years that AD trucks had frame mounted tanks, in 49 they went in the cab. The fuel filler tube on a 48 comes through the very bottom of the bed on the passenger side just above the filler panel at the rear of the running board, and held about 16 gallons. Correction on an earlier post on this subject: ford has not had positve ground since 1955 but their sender signal is backwad to GM's 0-90 ohm signal. Your gas guage will work but full will be empty and visa-versa with a mustang tank.
