There is absolutely no proof of that, only tin foil hat speculation and rumor.
There's no proof of anything when it comes to the Kennedy assassination, but Roger Stone sure make a good case for suspecting that LBJ was a driving force.
ML/NJ
Which was prescribed to by most people who actually knew him across the political spectrum.
But other than that...
Southern Democrats in that period should be assumed to be KKK until proven otherwise. Assuming they aren’t is the real “tin foil hat”.
LBJ was the ONLY one who benefitted by JFK’s death!