Lil Durk Calls King Von 'Serial Killer' On G Herbo 'In The Air' Collaboration

Late Chicago drill rap star King Von's name has been ringing out a lot this year, 4 years after his death -- and Lil Durk has just increased his homeboy's infamy on record!!!

On Friday, Durk's fellow Chicago drill rapper G Herbo revamped his latest album with "Big Swerv 2.0" deluxe edition, featuring "In The Air" with an alley-oop from Durk.

At the close of his verse, Durk references the legacy King Von left behind ... "Farewell, I'm gettin' up out the 'Raq, I'm a survivor Yeah, yeah, I turned a serial killer to a rapper."

If you recall, filmmaker Trap Lore Ross got heat from half the city of Chicago after he dropped his doc "King Von: Rap's First Serial Killer" last year.

Ross told TMZ Hip Hop at the time that he was a fan of Von and studied the info available ... leaked Chicago Police Department docs implicating Von in a murder after his death.

Lil Durk seemed to have recorded loads of music before his arrest for murder-for-hire Thursday night ... he was able to promote his upcoming album "Deep Thoughts" before U.S. Marshals apprehended him in Miami.

It may be a while before Durk and Herbo get to perform their latest number onstage ... Durk's being accused of funding alleged members of his Only The Family record label to carry out a hit on Quando Rondo, who killed his cousin instead.

He's currently in federal custody.