* Your Local Auto Parts Store: Stores like AutoZone, Advance Auto Parts, NAPA, and O'Reilly Auto Parts are good starting points. They can often look up the part based on your truck's VIN or engine and transmission details. Be aware that finding an exact OEM part might be difficult; they are more likely to have aftermarket replacements.
* Online Retailers: Websites like Amazon, eBay, RockAuto, and PartsGeek offer a wider selection, often including both OEM and aftermarket options. Again, providing your VIN or specific transmission details will help you find the correct part. Be sure to check reviews before purchasing from unfamiliar sellers.
* Ford Dealerships: While generally the most expensive option, a Ford dealership will have access to genuine OEM parts. This ensures the highest quality and correct fit, but comes with a higher price tag.
* Junkyards/Salvage Yards: This is the most budget-friendly option, but requires more legwork. You'll need to find a junkyard with a 1991 Ford F-150 in a similar condition to yours and ensure the linkage rod is in good working order before purchasing it.
Before searching, you'll need to be as specific as possible: Simply saying "automatic transmission linkage rod" isn't sufficient. The linkage system can have multiple components. Try to get the exact part number (if you can find it on the old part) or describe the specific rod you need (e.g., "shift linkage rod connecting the transmission to the shifter lever," or specifying the location on the transmission or linkage assembly). A picture would be extremely helpful.
Remember to check compatibility with your specific truck's engine and transmission type before ordering. The VIN is the best way to guarantee compatibility.