Method for providing precured innerliners (50) having a predetermined cross sectional profile for use as part of a pneumatic tire assembly used in a bladder-less shaping and vulcanizing mold. The innerliner (50) is formed from a continuous strip of elastomeric material (12) hot formed using a calender assembly (10) with a profiled calender roller (16). The formed strip is cured “in-line” in a press (38) having a profile matching platen (80) before being wound onto a tire building drum (48). After the pneumatic tire assembly is completed, the assembly is shaped and cured in a bladder-less mold, utilizing the precured innerliner as the impervious inner layer. Initially, the center region (62) of the innerliner is at least twice as thick as the lateral regions (72, 74). In the finished pneumatic tire, the innerliner exhibits a uniform thickness.