Even in these heady technological times, there’s one low-tech constant—the 18- wheeler. Because, if you bought it, you can bet a truck brought it. So it’s no surprise that a genre whose heyday was in the ’60s and ’70s, continues to put along like a Peterbilt heading up the Grapevine. One purveyor of all things sleeper cabs, is Chris “Sugarballs” Sprague, whose album, Hammer Down! is a paean to double-clutching storytellers such as Del Reeves, Red Simpson, Dick Curless, and Bobby Braddock. And wherever there’s diesel smoke in the air, killer guitar is sure to follow. In the case of Hammer Down!, the 6-string chores are handled by Dave Biller, a magnificent player who goes go from swinging country bop, to chicken-pickin’ call-and-response with Sprague’s lonesome tenor. Deke Dickerson guests on Johnny Horton’s “I’m Coming Home,” where he ably resurrects Grady Martin’s notorious twang. 10-4 good buddy! (18 Wheeler Records).