What's the fuel crossover tube do in a 4160 carburetor? why is it different than 4150

[Shawn MacAnanny]

I have a 3310-2 Holley 750. I converted it to a rear metering block. This would make it a 4150 correct? I bought a set of holley Adjust-jet metering blocks and installed them all, havent run them as i saw that the adjust a jets require a little longer fuel crossover tube to run on a 4160 carburetor. Now my question is what is the difference between a 4150 and 4160 carburetor? My adjust a jet plates installed perfectly in place of the jets and i just cant see needing the crossover tube.

I did buy the tube and have it here but i have no idea where it goes. Where would this tube go? Is it neccessary even though i installed a rear metering block?

[another69]

On 4160s that I've seen (with side hung floats), only 1 bowl gets fed. The crossover is to feed the other bowl. You may need to upgrade your bowls to center hung and change your fuel line. If you already have center hung bowls, you should be good.

[Shawn MacAnanny]

Oh yeah i definately have center hung float bowls with dual feeds. I see what you're saying now, that makes sense. Looks like im good to go then.