DOUBLE TROUBLE: Two of our fave-rave guitarists are Stevie Ray Vaughn and Jeff Beck. So imagine our delight to hear that the rock hot-rods (who are both signed to Epic Records) have teamed up for a 25-city tour, beginning Oct. 25 in Minneapolis. The duo (who are expected to do an L.A. date in early December) will alternate as headliners--and it's very possible that they'll be jamming together at the end of each show. . . . Linda Ronstadt's new "Cry Like a Rainstorm . . ." album features (count 'em) four new Jimmy Webb songs, including "I Keep it Hid" and "Shattered." . . . If you haven't seen the new issue of Hits Magazine, open it--and keep opening it--to find a special three-page nude centerfold photo of Capitol promo chief John Fagot. Labeled Hits Magazine's "Airplay Mate 1989," Fagot is pictured reclining on a couch, with a rose in one hand and a phone--a promo man's No. 1 weapon--in the other. Asked to describe Fagot's physique, Hits editor Lenny Beer quipped: "How do you feel about whales?" . . . And Rhino Records (the Westwood Boulevard record store, not the label) is touting its "Grand Opening Expansion" celebration with a series of wacky discount specials (You already missed "Mediocre Student Day" where co-eds with C-level or below report cards received a free bargain-bin album). Coming Tuesday is an event guaranteed to raise hackles at most record companies: "Home Taping Day," when blank cassettes will sell at a 20% discount. (Rhino is also hosting in-store live concerts, including one on Thursday at 8 p.m. by Dave Alvin).