273 vs 318

273 said
From what I've read the 2.02 X/J flow about 20 cfm more than 1.88 heads. And a 360 has 20 cid more to feed which needs about another 15 cfm more than 340's 2.02 heads to put it in the same cfm:cid ratio as 273/340. Just to put in perspective a 408 and 440 to be in the same ratio would need 260 cfm and 280 respectively or basically eddy heads.

i get it what your saying now. your talking head diff and cube diff is off by 30 40. i was thinking your were saying the head was off that far. my testing on 1.88 2.02 averages 10- 15 but the numbers do very from head to head quit a bit so even at twenty your close