Clint Eastwood isn’t known for his fashion sense (he’s not exactly running around in Armani in Blood Work), but the craggy actor’s making a splash in the clothing business. Orders for his Tehama sportswear collection, which he founded with fashion-biz vet Nancy Haley in 1997, have jumped 50 percent this year. The label, which includes resort-wear as well as a Bridges of Madison County collection, boasts such celeb fans as Celine Dion, Amy Grant, and Vince Gill. Available at select Saks Fifth Avenue and Nordstrom shops, the ”luxury lifestyle” line features such chichi items as microsuede polos and silk sweaters. Eastwood — who lends his name and image to the line, but leaves design details to Haley — says he didn’t expect the clothing to be so popular, but adds: ”There is something special about putting on a Tehama shirt first thing in the morning.” It must make his day.