Stock TB is 60 mm.
The stock Explorer linkage didn't come anywhere near fitting, so I made an adapter plate for the throttle linkage so I could use the 65 MM throttle body.
A trip to the welding shop with the explorer TB and the arm from your old Mustang TB would probably accomplish the same thing. I didn't have access to a welder, so I fabb'ed the plate in my shop. I took about 1.5 hours to do it, it was a measure, cut, and fit type of operation.
This is what I did:
Make a drawing of the position of the old throttle body linkage arm and its angular position relative to the centerline of the throttle body. Remove the ball stud off the explorer TB to make way for the adapter plate. Drill and tap a 10-32 hole in the linkage parallel to the TB shaft. Make an angle bracket out of 1" angle iron 3/8", drill a 3/16” hole in the center of each one of the legs. Then bolt it on where the hole was drilled & tapped. Then make a circular adapter plate out of 1/4" thick aluminum to bolt the two linkage arms together. Then bolt the aluminum plate to the existing linkage, and the angle bracket. Next mount the arm with the ball stud off the old throttle body on the adapter plate using the drawing to get the angle correct. You will need an aircraft type countersink for one of the bolts that secures the plate to the explorer linkage arm. It ends up being under the arm with the ball stud for the linkage. It works great and looks neat.
Also see Tmoss's adaptation technique at
http://www.veryuseful.com/mustang/tech/engine/ConvertingExplorer65mmTB.pdf for modifications to adapt the 65 MM Explorer TB to a Mustang
Another method is to remove the old bracket from your old TB by grinding off the end that is mushroomed over. Do the same thing to the Explorer TB and then drill and tap the shaft for a 10-32 machine screw. Put the bracket from your original TB on the Explorer, and install the screw with a big washer. You might want to put some Loctite on the screw threads before tightening the screw down.
