GrandSportC3

The only number I could find on it was on the main body and it was 6931.
This seems to indicate 750 cfm. The carb does have 2 metering blocks, so it is a double pumper and it has vacuum secondaries and no choke tower (and it appears that it came that way and the choke tower was not milled down. Does anyone know what carb this is?




I was thinking Holley 0-82750 - Holley 4150 HP Carburetors but the main body on that looks different

dugsgms74

Cant help you too much but I can tell you its not a double pumper. It is a dual feed vac secondaries.

79406

It is a vacuum secondary with two metering blocks, but not a double pumper. The secondary Excelerator pump would be on the rear bowl, on the bottom of the passenger side. Maybe you could find specific information on Holly's website or give them a call.

68post

What I find is that it probably is a part #R-6931A, which is a 4150-G, "1975 G.M.T.C. 427 engine California. Vehicle mfg.'s part #717724.
Someone must've sawn-off the choke tower !?

Looked-up in the Holley Carburetor Numerical Listing catalog.

Street Rat

It's hard to determine what you have unless you measure the venturi and throttle plate diameters. And possibly disassemble the carb to get some casting numbers off of the metering plates. The choke horn usually has the LIST number on it which would identify it. But it appears to have been milled off. The 6391 number isn't what you are looking for. I've included a link just in case you want to tear it apart and do some deeper digging. Good luck.

http://documents.holley.com/techlibr...al_listing.pdf

GrandSportC3

Right.. didn't even look for the 2nd pump... I looked at the extra metering block and I'm so used to Holley carbs being double pumpers if they have that 2nd metering block..

GrandSportC3

If the choke was milled off, it was professionally milled down and not just cut off. It looks like the carb came like taht as the transition from where the choke used to be to the rest of the carb does not show any differences in surface texture. I won't tear the carb apart at this point as it is working fine.. I was just wondering as I'm used to see the part number stamped on the drivers side of Holley carbs but this one does not have any numbers stamped on the drivers side..

Snoopysvet

Holley O - 3310
Only a guess

GrandSportC3

I had a 3310 before and it only has one metering block.
The 3310 is a 4160 and this carb is likely a 4150 type.

rklessdriver

It looks like a 3310 someone converted to use a rear metering block (Holley use to sell a kit to do this) and then milled the choke tower off.

The venturi size and straight boosters are a dead give away it started life as a 3310 750... plus the casting date looks like 1990 on the main body.

Why someone would put so much work in to such a modest carb is beyond me but maybe they just wanted to piddle.
Will

GrandSportC3

I don't see how someone would put so much effort into a 3310.. The car runs very strong with it.. it's a rebuilt matching numbers 327/300 with a bigger than stock cam, a Team G intake and that carb.. Someone put some effort into making this a good running 327. Feels definitely more than 300 HP, more like 350 or so..