Has anyone used LED Assemblies made by third parties in these mid-80's Ford F150's?

 

bump

 

Yes, I'm sure hundreds of people have.

Now you know.

 

did they work without flickering is my other question, or did it need a new led compatible relay
I only ask because I have an 86 f150 xlt lariat and I was gonna upgrade the headlights with either led type or xenon halogen bulbs with custom lenses

 

There is no headlight relay to begin with, and LED headlights don't require a relay, so: no, none of them needed a new relay.

The only LEDs I've ever seen flicker were cheap, or about to fail. If you buy some that flicker, return them ASAP.