I want to change my plugs in an 97 geo prizm 1.6 base model.I thought it would be easy to do. However I have gotten different plugs answers from two differnt auto parts stores.. NGK 2526 with a .044 (BKR5EYA-11) gap and a NGK 2087 with a .032 gap (BKR5EYA). what is the correct plug ??? The NGK website is no help. also what does the 11 mean???