basically the since leds use such a low votage it cause the fast flash. im not sure what style flasher is on the square bodies. i would guess an ep36 like the 88-95s take. U can pick on up at autozone for like 8 bucks. the tip I can give on finding it is turn on the signal and track down the clicking
guessing under the drivers dash behind the ebrake. the resistors also work great...I just dont wanna splice into anymore wiring than needed...They other issue that can sometimes occur with leds is the turn signals can light up in the gauges when the lights are on......The fix for that is to add some diodes to cancel the feedback.