i replaced my whole antenna assembly not too long ago with an oem antenna i ordered from one of the online toyota sites. you have to remove the inner fender cover, its about 10 10mm screws, and the antenna has a tube that bolts onto a bracket to support it. mine had cracked there so it would no longer support the antenna. the wire is connected to the base so you have to take the dash apart and run the new antenna wire to the radio. i think i just cut the old wire off the base and used it to pull the new wire through the grommet. hope this helps.
1994 Regular Cab Pickup, 22re, 5 speed, SAS, 4.88s, ARBs, 33s, and a sweet antenna spring