I have a '98 F150 4.2 with 5 speed tranny. Is it possible to swap the 5 speed with an auto trannny? Big hassle? Not a good idea?

 

You'll need a new computer, wiring harness, Flex plate, Torque convertor and of course correct transmission with attached speed sensors and such. Its doable, but not much point or gain. If you want a Auto bad enough, you may look into getting a different truck. Unless you have time and a donor vehicle with the auto in it then its not so bad, just time consuming.

 

Well, I'll write that down as "bad idea". Thanks.

 

Not necessarily, depending what you are trying to do. But generally it is a complex conversion, and if it is your primary vehicle then its a bad idea to immobilize it while you juggle work, life and the swap all at once.