[thorgir666]

Hi, my name is Torgeir and I live in Norway. Last summer I imported a 1968 Camaro RS/SS from USA. It has a 400 small block, muncie 4-speed and a 4.11 12-bolt rearend. Apperantly, the 400 is built, but that is pretty much all the info I have on the engine.It has Edelbrock Victor Jr. intake manifold, Dart heads,roller cam and a Holley double pumper. I have major problems identifying the carb. The numbers I got from the carb is; Body 6r(5533)B, metering block 1535b 34r.
It has been modified (grinding), and there is no choke on it. I belive its a race carb, and not suited for my application (Street/cruise).

Can I buy a choke kit for this carb, or should I get a new carb?
Sorry for my poor english.

Best regards, Torgeir

[Vintage 68]

If there is "no choke on it" - does that mean it was machined off and the top of the carb. is now flat?

If so, then - you can't refit a choke plate and parts to it ...

The easiest thing to do would be to replace it with a new carb. having a choke and the features you need.

As far as identifing the carb. you have;
A.) Does it have a Secondary Metering Block? If so it is a 4150 type - if not it is a 4160 type.
B.) You can pull the carb and check the throttle bore size to see about what CFM it is and know what size you might need to replace it with.
As a general rule here are the throttle bore sizes for the three (3) most popular sizes:
CFM - Bore size
650 - 1 9/16” (1.5625/39.6875mm)
750 - 1 11/16” (1.6875/42.8625mm)
850 - 1 ¾” (1.750/44.449mm)
There are all kinds of exceptions to those bores = a given CFM, but it is a good starting indicator of CFM rate.

And your English seems just fine to me
Much better than my Nynorsk

Hope this helps

[thorgir666]

Hi, and thank you for the quick reply.

Yeah, the top of the carb is now flat.
It has a second metering block. Measuring the bore size requires removing the carb from the manifold? Where to measure? Im not a engine guy, so it is my weak point (One of many weak points really).

I read somewhere that a 600/650cfm carb would suit the 400. I also read that many people makes the mistake of installing to big carbs on their engines. I dont know really, just have to belive what i read.
So a Holley Double pumper is what im looking for. Electric choke. How about secondarys? What should I consider?

I can teach you Nynorsk John

[thorgir666]

Hi again folks,

I am about to order a new carb for my car. The Holley Ultra Street Avenger 670 CFM, with electric choke and vvacum secondaries, or the regular Street Avenger. Whats the difference between the ultra and the regular one? Just the bling?

I'm also considering changing the fuel pump. It is annoying me because of the noise it makes. Its a electric Holley pump. I was thinking of a mechanical pump. Would I have to replace the fuel lines etc.?

[Nantooch]

Sorry can't help on the difference in the carb models, however as far as the fuel lines go. You will have to add some rubber line to the existing line in place of the elect pump. You may have to add some rubber tubing to the line where it enters the engine compartment on the passenger side and run it to the mechanical pump, then from the pump up to the carb. Small inconvenience compared to the humming of the pump or rattling it may cause.

[Steptoe]

Before ordering, decide what you are goiung to actually use the car for....
And order the recommened holley carb by holley
And if not doing 12 sec 1/4 mile runs and fuel lines stand diam....a good old fashsiond stock GM pump will do the job queitly and reliably...

[DjD]

The ultra looks to be "bling" and has clear not removable sight in the fuel bowl... If you are looking for better fuel economy with decent performance the Avenger is a good choice. The 670 may be small for your built 400ci mill...

If you want performance look at one of the Street HP's, they work really well but they don't have a choke if you need one... There's a more traditional 4150 with a choke, it's the 3310-C and is a 750 cfm carb that also performs well... If you don't need the choke the Street HP carbs are the way to go IMO but fuel economy is not one of it's strong suits...

[thorgir666]

Thank you all for the good help.

A blend between fuel economy and performance is desirable.. After the tip about 670cfm perhaps beeing to small for my 400, I started looking at the Street Avenger at 770cfm. $399 at Summit. Vacuum secondaries and electric choke. Is this suitable for my application? The Holley carb selector recommended this one, amongst others.

[DjD]

It's hard to over carb with a vacuum secondary carb. The secondaries only open if the signal they get from the primaries is strong enough to warrant them opening, sometimes vacuum sec is also refered to as "on demand"... My money says it will be a good choice for your 400...