Rolly Romero will step into the ring against Ryan Garcia on Friday night in some custom, "Marty McFly" Nikes ... and, Great Scott, they're cool!!!

TMZ Sports has learned Jose Coronado, AKA Aztek Kustoms, "deconstructed" the $40,000, "Back To The Future"-themed kicks so the 29-year-old could wear them in the ring for his huge tilt with King Ry ... and check 'em out, they're fully functional.

The shoes -- which were originally created by the Swoosh to honor the self-tying kicks Michael J. Fox once wore in "Back to the Future Part II" -- have operational LED lights and all the same markings of the OG ones McFly wore in the old-school flick.

Coronado tells us it took him about 50 hours to complete the project.

He also hooked up Romero with a matching warmup suit, basing the getup's imagery on the hoverboard McFly cruised around on in the movie. He designed Romero's team shirts similarly, too.

The sweet looks, of course, are nothing new for Aztek Kustoms and Romero -- the artist has been making boxing boots for the 16-2 fighter for years ... stitching up ones with homages to Bruce Lee, Frank Ocean and Prince.

Friday's Romero vs. Garcia scrap will officially go down in New York City's Times Square ... and great news for fight fans -- no need to get into a souped-up DeLorean to catch the action!!