[gearhead81]

Maybe I'm a DA for taking it, but a friend of mine gave me a Holley carb that he "modified" for racing. the funny thing is, all he did was cut off the air horn. no power valve, jets, pump cam, all stock stuff. he says it's a 750, but he loves to BS me about his car *****, so I don't automatically trust him. (He is still a good guy, don't get me wrong) But long story short, free Holley carb, no ID stamp, any other ways for me to tell what size it is?

[boss68]

Hey Gearhead 81,
A few things come to mind.
The metering block has numbers on it that would identify the model or at least the series.
The jet size and or secondary metering plate (vac secondary) narrows the carb id down further as does the throttle bore diameter and shooter size.
If you get a Holley carb numerical listing found in most Holley carb books as well as the internet or Holley, you can compare the items mentioned here and narrow it down closely, or positively identify it.
Just the throttle bore diameter(s) and jet size should give you the CFM from the specification charts if that is the only concern.
If the carb is a square flange, a 1-9/16" throttle bore is a 600CFM. A larger throttle bore will require a little more info, such as jet size to, determine CFM.

[gearhead81]

It's square bore, and it's a 1 9/16" throttle bore. Just took it apart, and it has a 6.5 power valve, and a set of #66 jets.

Thanks for the info.

[boss68]

Thats a 600!

[tomthecomic]

man your friend sucks and is grate at the same time. Free carb but not the right carb.

[gearhead81]

Like I said, he's a good guy, but you never can tell when he's blowin' smoke your ***, lol.

Anybody want two rebuilt 600's for a good 750?