Originally Posted by
Sw1tchfoot
Lots of people use 600 cfm carbs on 460's but if you think about it:
604 CFM on a 302 is 2 cfm per cubic inch
920 CFM on a 460 is 2 cfm per cubic inch
Just about everyone is running 600 cfm on 302's, yet how many people do you see running 900+ cfm on a 460? I'm beginning to think 750 cfm is in the ballpark.
1. The carbs do self adjust somewhat, since most all are vacuum secondaries of one design or another. You can only force the engine to "see" the front 2 barrels, the engine won't open up the rear barrels if it's not ready for them.
2. The 460 in most trucks is a loafer. Low rpm grunt is it's main claim to fame. It doesn't need much carb because of this. A 302 is a little screamer. Not much of a truck engine, but it can be used if the gearing is right. It can use the 600 cfm because of the higher rpm it runs. The 460 can certainly use ALL of the 750cfm carb if it's personality is changed by engine changes and gearing changes.