Experts - Can anyone help me identify what carburetor I have. I'm not having any luck locating id numbers. Thanks in advance!

 

It's a Holley "double pumper", probably around 700-800 cfm. Look on the metering blocks for a stamped LIST # or other #s.

 

There are no vacuum secondary double pumpers

 

I can tell you that “4100” is stamped on the metering block at the 5:00 arrow position in the pic above

 

Ah, yes. I always assumed it was the two center-hung float bowls that ID'd it. Learn something every day. Thanks. https://www.holley.com/blog/post/wha..._pumper_carb_/

 

750 or 850 cfm vacuum secondary that has had the choke horn milled off......
The secondary metering block is an add on kit......you can tell by its cleaner zinc color.....very common mod.
It probably a modified 3310-1

Jebby

 

Your airhorn choke tower has been milled off, so the list number is forever gone. However, if you measure the diameter of your primary and secondary venturi bores (not the throttle bores), you can identify the size, and narrow down the model number of the carb. If the carb is a 3310-1 (780 cfm) as Jebby is guessing, the primary venturi bore diameters will be 1-3/8". If the carb is a 650, the venturi diameter will be 1-1/4" (yet the throttle bores will be the same size at 1-11/16"). Likewise, if the carb is an 850, the venturies will be 1-9/16". However, the 3310-1 is a 4150 carb with the secondary metering block, and I agree with Jebby that your carb appears to be a 4160 model that has been converted to a 4150 configuration with a secondary metering block instead of the plate. That could make it a 3310-2 (750 cfm), but those carbs came with Ford kickdown linkage. Further indication that the carb is a converted 4160 are the hex-head float bowl screws installed in 3 of the locations on the secondary side, whereas the primary bowl has the old-style slotted screws at all 4 locations.

The carb is also equipped with the "quick-change" secondary diaphragm spring cover (which appears to be original based on the "patina"), which is not a feature found on the 3310-1 or -2 carb (it was used primarily on the Street Avenger carbs). But it could be a 3310-2 that has been modified with the secondary metering block and the quick-change cover. Either way, the carb appears to be a heavily modified carb and not anything in its original configuration... Jetting it will be a little tricky, not having any baseline spec, but things to consider are whether or not the secondary metering block is equipped with a power valve. This will determine the primary/secondary jet size split that you need to use (I'll bet your secondary jetting is pretty messed up...)

Lars

 

Thank you both for the info. That is super helpful and starting to make more sense. I’m not at home right now but will measure the Venturi bowls and report back. Is it at all possible that this is an Autolite 4100 with Holley metering blocks? I ask because that was the only number aside from the multitude of patent numbers I could find. Again, thanks you and Jebbysan both for the intel! Lee

 

No….definitely a Holley.

Jebby

 

Thanks Jebby!

 

Absolutely not an Autolite. It's a modified Holley.
See also edited and modified content in my post #7 above.
Lars

 

Thanks Lars...seeing as though I am not a carb tuning expert, it sounds like I would have a pretty difficult time figuring out how to tune this properly with so many different components cobbled together. I just bought this ‘68 this summer and although it has a freshly rebuilt 427 in it, I have not heard it run. Do you think that it would be better at this point to buy a new carburetor and save myself the headache of trying to muddle through? If so, would you have a recommendation?

 

Why don't you drop me an e-mail for detailed discussion - we're getting into a different topic with a "which carb is best for my car?" subject, which will usually result in a heated (and often irrational) discussion on the open Forum.
Lars
V8FastCars@msn.com

 

Done. Thanks Lars 👍