Brass center hung float for Holley 4150 four barrels and 2300 two barrels with needle/seat in the center of the float bowl. Matches Holley 16R-420A (old number) and 116-2 (current).
This is the long arm float used on the front bowl of all Holleys with this type of bowl, and all the back bowl of model 4150s. Model 4150 carbs have a metering block on the secondary side. Model 4160 carbs have a metering plate on the secondary side, so they need a shorter arm float there, which is F7119.
Used on single 2300 carbs with a center hung float (like List 4412) and on the center carb in Mopar Six Packs and Chevy Tripowers. Outboard carbs use F7119.
