I was wondering wat do I need to adjust to my 91 automatic mustang to add a biger TB I curenntly have a cobra upper intake and going to putt headers soon. Thnx
No changes need to be made to the computer or tune. You will need new gaskets to go along with the new TB.
For a street driven car with an AOD, a 65 MM throttle body is the best choice. The cheap route is the TB from a junkyard 95-2001 Explorer with a V8. They had a 65 MM TB as standard equipment. The Explorer TPS sensor needs have the connector from your Mustang swapped on to it since the Explorer TPS connector is different. The plastic insert in the TPS sensor is easy to pry out to allow the removal and replacement of the pins.
The old TB may be hard to remove since the mounting studs tend to corrode and seize up. Double nut them and use the bottom nut to turn them out, or use Vise Grips to remove them. Throw the old studs away when you get them out. There is no simple easy answer if they do seize up, just sweat and a lot of effort to get the old TB off. You can use bolts or threaded rod from the hardware store to replace the old bolts. Use lots of Never-Seeze anti-seize compound on the new bolts when you re-assemble things.