How to tell Carb model?

I thought I had a Holly 650, but I can't spot a model number anywhere. How do I find out exactly what I have?:confused:

Thanks for the help!

.....I identified my Holley 750 double pumper by the numbers on it. The motor is back in Kansas now so I can't go look to see exactly where the numbers were located but they were on the outside where I could see them. It had the model number on it {in my case xxx4779}. I then went to the Summit web site, put in '4779' in the search & my carb came up ;).... I thought I had an 850 but no it's a 750...... hope this helps ya, Bill
ps, if you still have problems I'd call Holley.....

What if you have no air horn? I'm not sure if mine didn't have one to begin with or if the choke tower was milled down by a previous owner.

I think I found a list number in a corner of the top surface of the main body... I'd have to check it again.

I hear ya... I found the number on Holley's list many moons ago and it agreed with what I thought I had (4150 750 dbl pump mech secondaries). I'll try to post a photo tonight for educational purposes....

Chris

With the square flange family of Holleys, there are 2 models 4150 and 4160.
The 4150 hase a metering block on the secondary side as well as the primary side. Therefore this carburettor is longer.

A 4160 has a metering plate on the secondary side that is covered by the fuel bowl.

Here is an example for a holley list 3310 you may notice that there is a space after this list number and it has a 1 or 2 after it. This suffix number denotes wether it is a 4150 or 4160 model.

So 3310 - x = 750 cfm vacume sec

- 1 = 4150

- 2 = 4160.

Now.... this applies to new carburetors and well looked after original old ones, as you can buy metering block kits to convert your 4160 series carb to a 4150 series.

Vacume secondarys and double pumpers.

This is easy the vacume secondary has a vacume chamber out the side. And no secondary accelerator pump.

The double pumper has a secondary accelerator pump circuit and they are allways a 4150 model carburetor. The secondarys are manually operated by a progresive linkage from the primary throttle shaft.