Lehighton telephones will be converted to dial operation in July of next year, according to an announcement today. New two-letter, five figure numbers beginning with the central office name "DRake" will become effective. At the same time, two-letter five-figure numbers beginning with the central office name "MOrris" will become effective for all Nesquehoning telephones, said R. C. Long, Hazleton district manager of Bell Telephone.