Originally Posted by ford344
they are calibrated at the factory so as to work as pairs in tunnel ram use.
Do you have any list #'s ( holley ) to go by ?
I've never heard of a 750cfm " calibrated " from Holley for a dual quad set up. I know they used model # 4160's for Dual Carb set ups due to the overall length when carbs are mounted front to back
I know of a few 4500's intended for Dual Carb set ups, like the 9375's but I have seen plenty of them used on single carb set ups and never seen them sold as pairs.