jcorkin

Looking for opinions on a carb for my 1974 omega with a 455 stuffed in it. It has stock rotating assembly and ported ka heads with a crower 56262 cam with .488 lift on intake and .493 lift on exhaust. It also has headers and an edelbrock aluminum intake. The car has been back halfed and has a 9" with 3.25 gears installed. I plan on ditching the th350 and going with a th400 and stall in the 2800 rpm area and possibly changing gears later on. I currently have my 670 street avenger on it that will need rebuilt soon so I am thinking of just upgrading and going to a 750 double pumper. I will most likely add nitrous next year as well but that is aways in the future. Any input on what carb to go with?

oldcutlass

I'm not a fan of a double pumper and an auto trans for the street. I prefer a vacuum secondary like a simple Holley 3310, or a 770 Street Avenger.

shiftbyear

A properly set up quadrajet will run very well, stock and superstock nhra classes require the factory carb. Some cars are running low tens with a qjet. It's also nice to see jaws drop when they see a stock carb and intake. Good luck.


http://www.dragracecentral.com/DRCStory.asp?ID=323693

Firewalker

Quadrajet is good when built right, but the Street Demon 750 with the black plastic middle should be even better, and you need a wideband setup for tuning on any setup, to tune it right.

oldcutlass

This is not true, while the wide band makes it easier, you can set up any carb the old fashioned way by reading your plugs.

wr1970

I agree with ERIC oldcutlass.

Firewalker

Not near as fast to implement nor as cheap that way for tuning, with things like AEMs costing so little under $200. It is one reason I would recommend the Street Demon over any other carb options or fuel injection.

Plug reading is something you learn over time, as in over many years as needed, for other reasons now a days for other problems and is a good window into what is going on in an engine. Few really know how, or do read plugs now a days, or set them with match book covers, or can tune by ear.

In the old days I shifted by ear and feel, and I and others blew a lot of engines, but tachs were few, expensive for what we made, and often inaccurate way back then and went out easily. Today we can buy tachs, timing lights and volt meters cheap, and get the job done right and faster.

Firewalker

Eric is a good guy with a ton of knowledge, but...

cutlassefi

Get a wideband, faster and simpler. Plus the heat range of the plug can change the color, and to the untrained eye potentially cause issues.
I wouldn't have any problem putting a double pump carb on a big block. I do it all the time with excellent results. Quick Fuel makes an 830 that would be perfect for your combination. I'd recommend that.
And be careful with the NOS. With a stock bottom end it'll be real easy to scatter it all over the street without proper tuning and caution.

74sprint

I agree with Firewalker in "Plug reading is something you learn over time, as in over many years as needed, for other reasons now a days for other problems and is a good window into what is going on in an engine. Few really know how, or do read plugs now a days, or set them with match book covers, or can tune by ear." As soon as you idle that engine the plugs change color.

I also have an 'X' body, a 74 Ventura though, with an Olds 455 in it. I started off with a Sig Erson Torquer cam with similar specs (as your cam) and a 800 cfm quadrajet. My quadrajet, which I still have, has an adjustable spring loaded air door which makes it nice for the street. But setting the air/fuel ratio properly was a pain in the a*s. Whenever I needed to change the primaries, either jets or rods I had to take the top off of the carb. A complete and utterly pain in the a*s. Mind you my quad also has a barometric compensation circuit so once I got it set at the track I was able to forget about it for 5 years. I have since gone with a lot bigger cam and a Holley.

I would go with a Holley 800 or 850 double pumper for power or for gas mileage a 800 cfm quadrajet or a Holley 750 vac secondary and get the spring tuning kit for it. With that cam, which isn't very big, the latter carbs will work better for you.

As far as tuning a carb I now use this https://www.14point7.com/products/slc-free I just shove it in the tail pipe, clamp it, and away I go. This thing beats the hell out of any thing else out there and just $95 with sensor. Alan To is a straight up guy and is very helpful.

Ray

RayK

I use a Quadrajet on my 462 Pontiac. I build them for a living, and we have some out there running low 10's. With that said, what is the planned use for the Omega? Strip only? Street/strip?