289 vs 318 ..... Ford vs Mopar

My bet is that the 289 cars had 3.5-3.9 rear gears and the 318 cars had 2.7-2.9 gears
All my cars with 289's have 2.89:1 and 2.94:1 gears
65 and 68 Fairlanes 67 and 68 Mustangs
302 cars came with bout the same gears 70 and 84 mustangs.