350 motor/ what size Holley you running
 

what size carb you guys running on your 350???

Re: 350 motor/ what size Holley you running
 

Stock 350? Vortec 350? Makes a difference.
Was running old TBI 350 Stock with headers and aluminum intake, topped with Holley Street Avenger 570. Vortec moves more air so can afford bigger with ease so can go to 600-650.
I ordered my Vortec 355 as a crate and had it cammed, lifter, and rockers upgraded......top off with being vortec, I went with Dual feed Ultra Street Avenger 670.

Re: 350 motor/ what size Holley you running
 

You need 600-650. Not any bigger.
Posted via Mobile Device

Re: 350 motor/ what size Holley you running
 

I'm gonna disagree, just sayin .. we need to know what's in it, heads, etc. I had a 355, built by Race Engine Design here in Chattanooga and ran a 3310 on it. 70pri/76sec and it was spot on. Stock 350, yes.. 600-650 but if it has some work done maybe not so much.

Re: 350 motor/ what size Holley you running
 

I have a 670 Holley SA carb on my 69, its a 350 with stock heads and cam but has a intake headers and MSD HEI. I tossed around getting the 570 Holley but knew one day it would get a better set up motor and knew the 670 would work untill then. Truck runs great with it on there , I also called Holley and talked 5o them about it and they also steered me to the 670.
Bone stock a 570-600 is a good pick.
Posted via Mobile Device

Re: 350 motor/ what size Holley you running
 

Motor has dart 200cc runners. With 64cc chambers
About 10 to 1 comp. cam is small with .480 lift
Dart duel plane intake and hei dist.
Stahl is 2400.
Posted via Mobile Device

Re: 350 motor/ what size Holley you running
 

As others have said--it depends on how its built----but mainly what youre doing with it.

If youre driving to and from work and to the local gitngo---why would you want a gas guzzling double pumper?
The two biggest mistakes people make in street engines is too much cam and too much carb. If youre gonna race it, might be a different story. But low RPM grocery getter dont need a .488-.564 lift cam and a 670-750 cfm carb. They sound good thumping at the traffic light---but with high fuel costs---who needs the thump?

Re: 350 motor/ what size Holley you running
 

Yep, the Street Avenger 670cfm electric choke and vac sec would be a good choice right out of the box IMO or you could get into a 3310 and dejet the primaries a little like I mentioned earlier. I think the 3310 is 72/76 out of the box but we just stepped it down a little in the primary circuit to save a little fuel.

Id do between 670-750 personally. You have enough motor to do 750. The 3310-4 is 780cfm if Im not mistaken.
Posted via Mobile Device

Re: 350 motor/ what size Holley you running
 

Now that we have a little specs on your motor: I will give you a fair heads up. All Holley carbs are supposedly flow jetted to run right out of the box. This however is slightly true......They are also all going to be set a little on the rich side. You will have to lean down a 670 with t he specs you have given.
I would recommend you look at a standard single feed Street Avenger 600. You will be much happier with the performance and wont run into a super rich running carb issue. The Double Pumper Dual Feed 670 will most likely leave you sick of smelling unburnt fuel.
If you trust your motor, buy a mid size carb like the 600, put it on and hook it up. Should start right up for you. Then take it to a dyno/tuner shop and get it fine tuned for optimal performance. Money well spent. Not all Dyno guys will run your motor to its threshold, especially since you will be only looking to get fine tuning on the carb. Its when you ask them to find your HP/Torq perfomance that risks can be heavy.

Re: 350 motor/ what size Holley you running
 

I have access to a 650 dp and a 750dp

i will try the 650dp first...


thanks!!!!!!:gmc2:

Re: 350 motor/ what size Holley you running
 

Will be more streetable with the 650 over the 750 for sure.

Re: 350 motor/ what size Holley you running
 

I know the 670 SA I have has vacuum secondarys and does not run rich on my motor by any means and your motors is built better then mine, I would not think twice about a 650-670 carb on that motor myself.
Posted via Mobile Device

Re: 350 motor/ what size Holley you running
 

I finished up my new intake manifold and carburetor install last weekend.

Edelbrock 7101 and Holley 3310C (750). The truck has a 350 with a VERY mild cam.

It runs extremely well, definitely picked up some power too over the Quadrajet and Weiand 8004. I've only put about 20 miles on it since we've tuned it, but I'm loving it so far. I also haven't calculated the mpg difference, so I can't speak to that. But it drives just as tame as the Quadrajet.

http://i131.photobucket.com/albums/p...ps56fcc279.jpg

Re: 350 motor/ what size Holley you running
 

I agree with the statement about overcarbing.I think the best bet for a street carb is Vac secondary with about 600-670 cfm.The vac signal seems to work to give you better low end/low rpm power without sucking fuel.

Re: 350 motor/ what size Holley you running
 

I actually have a very similar motor to your. World product dart two heads with 10:1 comp only my cam is bigger. I have a 600 vaccuum seconday on it and had it dynod. The air fuel was great with 73pri jets up to 5200rpm and it ramps up hard to a lean mixture. I need to put a 650 on it. Dynos dont lie so thats my two cents
Posted via Mobile Device

Re: 350 motor/ what size Holley you running
 

those large runners aint goin to b so good on a daily no matter the carb