I think a single 750 cfm carb on a Performer RPM will outperform two 650's on that dual quad manifold. If you are after looks go for it, but there is no real performance advantage to 2 fours on your particular engine.

JMO

 

agree with eric. 2x4 makes for some cool bling, but there's no power there until you're into tunnel ram full race territory, and there will possibly be drivability issues.

 

Use two AFB type 500 cfm'ers instead.

AND the "Bling" is fine to me b/c it is an old-school look!

But it will run better with the 750 and a good high-rise, imho too....

pdq67

 

You "might" see a little gain in performance in the very upper end of your power band. The problem is what little you gain up there you will give away down low. 1300 CFM is a lot of carb for a 350 cube street engine.

I agree if you want it for looks, go for it. If you are truely ater performance, save the money and buy a nice custom built double pumper. It will be cheaper and give you the performance you are after.

 

Two 4's? Fughedaboudit if you're driving this thing on street regularly. No way your engine needs anywhere near that CFM flow. You'll have horrible low-end performance, IMO...................

If you want cool bling factor then do a small blower, which will still be very driveable, as well as undoubtedly add a ton of power.

-

 

If I do a small blower then I asume the guts of my engine will need to be upgraded.

 

Edelbrock claims their 2x4 w/the small carbs gives pretty good street manners... and you could always look into a prograssive linkage that doesn't touch one carb till half throttle (not my favorite solution, but strill a possible)
Dual quads makes for some pretty bling a car shows no doubt.

 

i ran 2 660 center squirters on a tunnel ram about 10 years ago on a 4x4 sand drag truck i used to race. the engine was a 355 w/track 1 heads, 11-1 cr, 265ish duration @ .050 solid flat tappet cam. on a 100 yard track my best time with the 2 holleys was a 5.8 second et. with a single 800 holley on a victor intake my best time was 6.1 et. i gained 3 tenths in a 100 yards. big difference. the final drive ratio was in the 7-1 ratio range with 35" tires. it worked well because traction was very poor & combined with a huge gear ratio the rpm's would climb very fast. i did drive it on the street every so often & it was a pain in the butt! always stumbling & loading up. i would go with the other guys idea of a small or even a 6-71 roots blower for the WOW factor. dont run a bunch of boost & you can make a blower run on just about anything.

 

If I do a small blower then I asume the guts of my engine will need to be upgraded.

Absolutely not, your engine should be fine. You could add a hundred or more ponies with no sweat and no damage. I mean, just about anyone here would tell you it'd be safe to run a little shot of nitrous, say 100hp or maybe 125hp. But it sounds like you want bling factor (no bling with nitrous), so use the blower to add the hundred ponies and you'll have tons of bling to boot.

The key, as with any power adders, is moderation and attention to detail. Obviously, setup is crucial, limit the boost to a conservative level, retard timing, etc.............

-

 

Schoon I don't have a clue how well two carbs will work, but if you can, put them on, two carbs like that under the hood, that is a real treat to see.
It's rare that I ever see a setup like that, but when I do, the first thing that comes to mind, is this guy understands the program.

Put em on, and give us pictures.

Rob

 

My engine specs say the internal parts such as rods etc are good for 500hp.
I am somewhere around 450 now. The blower will put me way over the safe zone. Still think it is ok to add blower?

 

My engine specs say the internal parts such as rods etc are good for 500hp.
I am somewhere around 450 now. The blower will put me way over the safe zone. Still think it is ok to add blower?

Those specs (hp and rpm limits) are most always conservative, they have to be, otherwise everyone would continually be returning "defective" engines. I did use words like "moderation" and "conservative" though.

:beers:

-

 

I had a high school friend way back then that ran a dual quad setup on a low rise intake. I don't remember all the specs but it was a 350ci with flattops not sure what heads. It was in a 67 Nova with a welded up rear end and fairly low street gears. Talk about a surprise that car would actually run and I do mean hard and quick. I'm not saying it wouldn't run better with 1 carb but it is possible to run them. He drove the car daily it was his only transportation.

If you want the look you need to find some serious Carb guys that will work with you to get them setup right. It more than likely wont be a buy 2 carbs and a manifold and tada your finished. But a small blower is a nice option also.

 

fyi,
I saw in a magazine Edelbrock remade it's 2X4 inline manifold. The old one's ports would steal charge from each other. The newer manifolds are much better but port lengths are still not ideal.

 

Edelbrock did release a new 2*4 manifold. I have one on order from Summit. It has been back ordered for awhile. The new SBC dual-quad manifold is based on the Air-Gap design. In fact, it raises the carbs ~1.5" from the original design according to the techs at Edelbrock.

I first saw the new manifold at SEMA this past November. At that time, the release date was mid to late Jan/06'.

lg

 

I have a pretty good idea of what's going on but 2 carbs or a blower may be a little over my head. I am going to ask a guy I know who builds race engines etc and see what he says. Another concern I have is if the height of a blower will it hit my hood, the other thing is I have a cowl hood and I am not sure if 2 carbs will fit in the circle. I really don't want to cut the hood.
It will be a tough choice betwwen the carbs or blower. They both really look good when you pop the hood.

 

I have an early 1970's Offy crossram (2 holly 600 cfm's) on my recently completed restoration of my X77 Z/28 if you look at the underhood pics you will see I had to slightly modify the cowl hood. I hope to add the proper repro air cleaner assembly soon but may have to modify hood further. It really rips both low end and top end.

http://69z28finishedjan906.shutterf...y.com/action/slideshow?a=67b0de21b3363f0fa4cf&auto=1&idx=-1&m=1&d=1140366443988

 

What about the original Z28 with Cross Ram. How did they perform so well with a small 302.

 

Cost!

And I don't think it did below 4,000 rpm!!

pdq67

 

I have been thinking of this new edelbrock set up my self, does anyone actually have this set up and how do you like it.

I am putting on a 350 w/ the votech headsand 4 speed, in a 63 nova wagon