This might help. 400 - 6.6 GM, 5.7 - 350 GM, 5.0 - 302 GM, 5.9 - 360 Chry., 289 - 4.7 Ford, 302 - 5.0 (cough 4.9) Ford. So i would have to take a guess that its about a 296 and 318? But those are just guesses.