The #180 blades are 1-3/4", which leads in the direction of 825 cfm or bigger, but to know actual size from there we need to know the actual venturi size, at it's smallest point, which is typically at the same height the carb booster rings are hung in each barrel.

Venturi size will be in the range of 1.400" to 1.560" and there are about 3 steps in this range, so a fairly accurate measurement is needed, you'll need calipers or a really good steel machinist ruler/scale.

It would also help to know what style and approximate diameter the boosters are. There are a couple different size conventional "dog-leg" or dropped leg boosters offered, along with the larger diameter annular booster type.

 

The venturis are 1 5/8 and the smallest point of boosters are roughly 5/8", then they step in to a machined surface with 8 discharge ports

 

Im new at this,lol,i somehow responded on the bottom of your post, 1 5/8 venturis at smallest point and i believe annular boosters and smallest id is roughly 5/8",there are 8 discharge ports

 

This leads me to say you have an 820 CFM Annular Discharge Carb, based on the approximate sizes you've given.

 

I have a known 800cfm holley and plates are 172 and the venturis are much smaller,with downleg boosters,i was told by seller that what i had was a 930cfm claw BG

 

If you take the same venturi size, and same throttle plate size...in this case we will use the BG sizes of 1-3/4" throttle plate and 1.562 Venturi (this is the largest standard Holley base 4150 bolt pattern carb BG made in the Demon line)....using standard dog leg boosters it is 1000 cfm rated, but the same carb with annular boosters is only 820 cfm....the increased size of the annular booster increases fuel signal to the metering block, but decreases the total airflow ability of the carb because of the space the annular booster takes up in each throttle bore.

With that said, very little info is available about the Barry Grant Claw series that was sold before he created the Demon line...this is why I stressed very accurate measurements of venturi size....is it 1.562"??, which is the largest listed venturi, there is no 1.625" like you posted in a previous post, at least in the Demon line.

Only way this could be bigger than 1.562" is if this is a Dominator flange carb(Holley 4500 flange, or "King Claw" carb)....does it fit a standard Holley intake, or fit a Dominator flange intake??

Could be it is possible that it is a 1.625" venturi / 1.750" baseplate Claw carb, and those sizes would point to a possible 930 cfm rating, but this is a poor low to high size ratio for good fuel metering, and may be why this size was not offered in the later Demon lines. I can't say for sure, the Demon tuning book I have doesn't give much on the Claw series that came before the Demon series.

If you have a definite measured size to the venturi, within .020", I can then tell you exactly what you have....that's the reason I stressed that before and suggested calipers, eyeballing with a ruler is really not accurate enough unless you are a machinist and used to looking a graduated steel scale closely.

Not saying what you have been told is wrong, just saying tighter measurements, or if you are sure about that 1.625" venturi measurement and whether it is 4150 base pattern or 4500 base pattern will nail it down.....I feel that you, like myself, would want to try to know exactly what it is and not take a sellers word for it, some are clueless and just believe what they were told by the guy who sold it to them.

 

Its a 4150 flange,BG is embossed on top flange,body is gold,those numbers were etched on side of main body,i did use calipers,had a piece of tape on one side,held calipers square and marked on tape,then measured calipers with my 6" scale,that number is pretty close to what i said,i have a set of snap gauges at work,when i got this carb 10years ago,it came with what was left of the rebuild kit,and it was for 4150 bg claw,the venturis dont appear to have had any work done to them,the id of boosters is what i wasnt able to get an accurate measurement on,i used my 6" scale to get the measurement,but my eye is very accurate,i have better tools for such a task at work in my box,these venturis and plates are much larger than my 800 dp holley,i know this is before the demon series came out,and your theory sounds good,you obviously know what you are talking about,now im even more curious to what i have,its a very nice carb in excellent condition,just outdated,its all back together and back on engine,i got a 4150 holley rebuild kit,mine used the biggest mainbody gasket in kit,and i dropped powervalve down to a 4.5,my engine produces almost 9" of vac,

 

I would say that you got decent info from the seller then, with an 1.625" venturi and 1.75" throttle plate size it would be somewhere in the 900's even with annular boosters, and the annular boosters are probably the only reason this venturi sizing works at all.

Appears the seller wasn't jerking you at all.

There was a removable sleeve (RS) Race Demon that has an 1.590" venturi and 1.750" baseplate, IIRC it is 925 cfm with the RS type Annular booster, which is slightly different than the non- removable sleeve boosters, so that also points in the same low 900's direction for you.

A buddy has an Race Demon RS, with a couple sets of the removable Venturi sleeves...it can be 825, 975, or 1025 depending on which sleeve and booster set is in it, and it was the only reason I bought the Demon tuning book was to figure his out, seller told him it was 725, which I could tell just from knowing Holleys that that wasn't right info.

Book doesn't cover much on the Claw series though.