I have a 1997 f250 351w 4x4 with 272k miles original tranny/ motor and runs strong. I'm wondering about some common problems that may occur and potential upgrades. I make okay money here in FL, but not trying to break the bank. I've already re routed the serpentine to exclude the smog pump since it locked up, replaced water pump and clutch for the fan. A/C also gave out but I havent even tried fixing that yet . I'm thinking of some cheaper upgrades until the motor goes and then what kind of motor would fit under the hood. I cant find much anywhere for a 1997 351w