Abstract: A method for transporting heat exchanger fins and forming a core subassembly for a heat exchanger uses a universal fin tray for all subassemblies instead of different tray sizes for different core subassemblies. The method includes indexing core plates forward under a stationary fin stuffing box, loading fins into the universal fin tray, indexing the loaded fins forward one at a time corresponding to the number of fins required, pushing required fins into the fin stuffing box when indexing reaches number required for the core subassembly, and pushing fins out of the fin stuffing box into the plates forming the core subassembly. A universal fin tray size, a stationary fin box, and a stationary cut off are used for all core sizes.