Carb recommendation

[superbird77]

Hey all, I am trying to figure out what carb make and model will work best on my 69 RR build. My plan so far is my 383 with a muscle motors 451 stroker kit, 440 source heads, Holley street dominator intake, comp XE274 cam, hooked up to the A833 4 speed. 3:23 gears out back, manual brakes and steering. Should I go with vacuum or mechanical secondaries? What's CFM should I look for as well? I would like something that's reliable and has good response. Thanks!

 

[prplcar]

If the car is light(under 3100lbs) mechanical work great. I had a 750 holly double pumper, car was fast. It was a 73 Dart with a 383. My current car works better with a larger cfm and vacuum secondaries.

 

[Dennis H]

Coronet weighs 4000 pounds. 850 Demon works for me.

 

[Rocketman]

I have a 750 CFM Holley on mine after adding the Edelbrock Top End Kit and a .545 lift cam, it runs great!

 

[snakeoil24]

Either quick fule 800 or Holley 950

 

[Travis_216]

I had a Holley street avenger 670 on my 440.. I just bought a 870 street avenger vacuum sec and electric choke for it now. It's only a mild 440, 268/276 Lunati voodoo cam, tci streetfighter converter, edelbrock performer intake manifold and 3.91's in the rear. I would recommend the same carb for yours, a Holley street avenger 870 vacuum sec electric choke. Holley has been around for years and make great carbs. Pretty easy to tune as well!

Travis

 

[superbird77]

I spoke to Holley today and their advice was a 750 double pumper with mechanical secondaries. I was also told not to go much over 750 cfm or i will end up with hesitation and poor cruising manners. Any thoughts on their advice? I seemed to think vacuum secondaries were better for a Roadrunner with a manual 4 speed, i am not sure what way to go on it.

 

[Plumcrazybee]

Maybe I missed it, but what exactly are you going to do with the car? Seems like a lot of advice on carb size, and configuration, so I probably DID miss what the car was going to be used for. I do tend to miss things at my advanced age though…..

Yeah, I definitely had to have missed what the car was going to do, because we all know that one of the most important pieces involved in making a decision on what carb to use is to be honest with ourselves about what the car will do for most of the time. Some say it may be THE most important part of the puzzle. Personally I think it is extremely important, but just one of many pieces to the plan.

Yep, being a smartass. But only half joking. So if I went off on a wild tangent, and "assumed" you were going to take it to cruise nights, drive in for ice cream, occasional trip down 1/4 mile (whether at the track, or out on some country road) and just out for a nice ride with your family….it would be very easy to say go with a vacuum secondary. In fact, it would be a mistake to go with a double pumper in this scenario just from the drivability sense. Of course, this is just my opinion, and I based it on details that I completely made up. :icon_thumright:

Vacuum secondary carbs make a car a sweetheart to drive, allow you to run a bigger carb (intentionally or by mistake) than you really need, can help make it easier to live with a cam that maybe you didn't really need, and have absolutely no downside in the situation that I made up for you. Only thing I can even come up with is it is way cooler sounding to say, "Double Pumper" than it is to say, "Vacuum Secondary." Double Pumper even sounds fast, or maybe fast AND illegal.

Lots of carb companies out there. Yes, Holley is one of them. And I used to use their carbs exclusively. But other carb manufacturers have pushed technology pretty far past where Holley has been sitting for decades. Yes, Holley is really stepping things up lately, and I blame that on the competition. And we all benefit from it.

If I am way off on your intended use, I apologize. The good news is if your intended use is strictly drag racing, carb size and configuration are simple to come up with. It is when we start compromising because we want our cars to do a lot of things well that we need to pay more attention to what it will do MOST of the time.

Best of luck on your project!!

 

[coloradodave]

Plumbcrazybee: Best response of the group and entertaining too...

 

[Plumcrazybee]

Plumbcrazybee: Best response of the group and entertaining too...

Why, thank you Mr. Colorado! My wife says I always crack myself up. So it feels good to have at least one other person appreciate my dry wit…LOL.

 

[superbird77]

Thanks Plumcrazybee, you're not far off since its gonna be a street car. I will hit the strip once in a while but nothing serious. You're spot on about realizing what you really need versus what you think you need. I ended up deciding on a 780 holley street avenger as its affordable and has a good reputation it seems. Hopefully it's enough cfm and is a decent carb. You sold me on vacuum secondaries, done deal.

 

[Plumcrazybee]

Thanks Plumcrazybee, you're not far off since its gonna be a street car. I will hit the strip once in a while but nothing serious. You're spot on about realizing what you really need versus what you think you need. I ended up deciding on a 780 holley street avenger as its affordable and has a good reputation it seems. Hopefully it's enough cfm and is a decent carb. You sold me on vacuum secondaries, done deal.

Oh jeez…the pressure, I can't take it, lol…I don't see any possible downside to your carb pick. Have used that specific carb on a few different engines. And unless you plan on spinning that 451 to 8,000 rpm, it is more than enough carb. But again, my opinion only. I sure would like to see that car when you have the stroker done. Should be a hoot.

 

[WileE]

Plumbcrazybee: Best response of the group and entertaining too...

I second that !

 

[superbird77]

Oh jeez…the pressure, I can't take it, lol…I don't see any possible downside to your carb pick. Have used that specific carb on a few different engines. And unless you plan on spinning that 451 to 8,000 rpm, it is more than enough carb. But again, my opinion only. I sure would like to see that car when you have the stroker done. Should be a hoot.

Thanks again, I should have the car finished by late summer so I will post some pics and give some details on it as i go. I decided on using the muscle motors stroker kit instead of the 440 source kit. Both seem good but muscle motors is local to me and they seem way more interested in helping me when I called asking for setup help. Cost looked to be the same also. I had thought about going to a larger 496 stroker kit but thought it may compromise the street aspect of the car.

 

[Plumcrazybee]

I also cannot come up with any downsides by going with Muscle Motors. And finding a company with as great a reputation as they have, being local for you, and immediately showing you that they want your business would shove me in that direction if I were you too.

Definitely share the build-up. I have a 400 builder engine that I keep eyeballing in my garage. But have to keep reminding myself to get the Bee done first, before any other projects. But there is this Duster for sale locally, and it is entirely gutted, and work has started on tubbing it. And….nope, no projects until Bee is done…See? I can barely contain myself!