I spoke with my contact at Tow Ready and he informed me that the threads of the Anti-Rattle Device # 63232 that you referenced are 5/8 inch in diameter with 11 threads per inch UNC2A.
I attached a review for this product for you to check out also. view full answer...
When buying the Upgraded Circuit Protected Tail Light Converter Hardwire Kit w/ 4-Pole Connector and Circuit Tester # 119178KIT for your 1992 Toyota Tercel you will get a Wire pigtail measures 18" long and the 4-Pole trailer connector is 60" long from converter box.
I've included some videos for you so you can get a good look at what comes with the kit and see how this installs. view full answer...