Remember when that fight was talked about. Benny was on TV a few times, destroying his opponents. NBC tried putting something together back then.
In a street fight with no holds barred, "The Jet" dismantles my man "Hands of Stone." However, in a regular boxing match, Duran would eat Urquidez alive.... Same as Bruce Lee of 1972 killing Manolo Pacquiao of 2010 with ease in a street fight where everything goes.... Now, in a pro boxing match with the use of hands and fists only, well, things get real tight there for Bruce Lee.... Rules complicate certain things when it comes to fighting..... MR.BILL
I think right after Benny destroyed a pretty good fighter (Billy Jackson), NBC was trying to promote a fight between the two. Of course, it was to be Benny with his Kick-Boxing style vs. Duran (conventional). But contract talks stalled.
American "full contact karate" rules -- Duran probably wins. I think the above-the-belt kicking limitation would deprive Benny of part of his firepower. Anything closer to Muay Thai or MMA (leg kicks, knees, elbows, judo throws, etc.), and Benny wins.
I remember low-budget features back in the late 70s like "Jaguar Lives" and "Force: Five." It starred Karate champs Joe Lewis and Benny Urquidez.... MR.BILL
In late 1977, The Jet was on a TV fight. The Jet challenged Duran, but at 140 lbs. A 2-fight match, one under 'kick-boxing' rules, and the other a 10 round 'boxing' match. The Jet then went on to destroy Billy Jackson in 4 rounds. Duran abandoned the 135 lb title, and went on to campaign at 147 lbs. in 1978.