Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
leds are diodes, so they will only work plugged in the right direction. If they aren't working, flip the bulb around. They are also cheap so chances are some will be duds rights out of the box.
btw, a throttle body spacer on anything except a carb or TBI motor is a waste of time and money.
A k&n FIPK or bigger rockers would have been more therapeutic. Not sure if you have them.