My new 408 build , but what size carb?

[340Duster247]

So I've started a new engine build for my 71 duster. The 340 has issues beyond repair so now it's going to have a 408 stroker. Here's the specs.

Scat forged balanced rotating assembly. Flat top
11:1 compression
Eddy rpm heads
Air gap intake
Lunati cam 242/252@50. 533/552 lift. Hyd/flat
TTI headers.
NOS 100-150shot plate

3800 stall. 430 gear

So what cfm carb am I looking at for this setup

 

[jhnycuda]

I'm building a 408 right now myself, plan to use a 750 Holley double pumper, mine will be 9.5-10.0 compression, solid flat tappet cam .243/.251 @.050, 1 5/8" header, RHS iron 2.02 heads, 3.73 gear, 28" tire, I have a Victor, a Torker 2 and a LD340 intake to choose from, leaning towards the Victor to kill some of low end, may add a 100 shot as well.

 

[340Duster247]

Sounds badass!!
How do you think the victor will do for street manors. I've thought about a victor but always been told air gap is the better choice.
I have a 750 dp now but was thinking the 408 would want more.

 

[rsaun191]

Great looking duster.800 cfm at least with your combo and I'm with air gap for intake.Thats what I got on my stroker.

 

[70aarcuda]

950 holley

 

[Woods74]

That paint is killer, what color?

 

[BrianT]

I'll be running an Edelbrock Thunder series 800 cfm carb on my 408 if the machine shop will ever finish!

 

[340Duster247]

Thanks guys. Right now I have a 750hp dp and access to a 1050qf. I'm thinking 850
It's actually vinyl wrapped. Mettalic matte charcoal.

 

[jimjimjimmy]

950 holley

x2 950 hp

 

[rumblefish360]

x2 950 hp

X's 3!

 

[stroked340]

You'll love that cam ran it in my 416 and have one in my current 360 same 3800 stall converter and 4.30 gears..i'd go Quickfuel 850 best damn carb i ever bought..

 

[FredS]

850 DP is my vote. Lots of potential if you decide that cam isn't enough. That stroker will have plenty of bottom end too.

 

[j par]

I didn't stop at one carburetor, dual quad tunnel ram ! !!

 

[grimreaper]

My experience is that the 850dp is pretty big carb. The 950hp is a better solution.

 

[340Duster247]

Wow thanks guys. I just got back from a local car show and my parts guy ( who's also a best friend) thinks the 750 will do, but I disagree and i see you all would too. I'm looking to squeeze as much as I can out of this combo. Propbally gonna port the heads this week too.
So it's between 850 or 950... Now that I need a new carb brand name is another option. Holley, proform or QuickFuel. I've personally only used holleys but would like to hear your experiences with others.

I shouldn't get off topic but Any ideas what ETs I should expect with this combo while spraying a 100shot.
It has drag radials 315s. And caltracs
My dream is to make 10s. I'd be happy with that.

And for those who noticed...I know. It needs a cage/roll bar

 

[SRT_DSTRHOLC]

850 ultra hp or the old style 950 hp

 

[Woods74]

Been doing any wide band tuning with that? I'd recommend that when you pick your carb.

I'd also check this out:

http://ls1tech.com/forums/carburete...t-level-holley-tuning-serious-ocd-tuners.html

 

[340Duster247]

Yah there's a wide band already installed. (Innovate).
Thanks for the thread. Good stuff there!

If Holley,Will definetly be ultra hp as that's what my 750 was

 

[fishy68]

I'd say 850 bare minimum. As a side note I think you'll find that the 4.30 gear your using now that I'm sure worked fine with the old 340 will be very low for the stroker. With the cam you have I doubt it'll rev past 6k (and make any power). With 4.30's your gonna run out of gear real fast

 

[winstoninwisc]

I just picked up a mighty demon 650 for mine and it rocks real good carb builder . I have my old 750 dp vac seconds I could give you his name and # and he will build it up for you I would let it go for 100.00 +25 to ship to him in pensylvainia if you would like .
pm me direct if you would like his # to call and talk to . its all he does is build carbs , or he has a whole shop of them , tell him your build he will make it Dance .his name is mike
, and I think he:s worth the call , just for the knowlage . mike knows motors , he will put the right gas station on that motor.. Jon

 

[Abodybomber]

950 holley

This... Great basic carb.

 

[stroked340]

Quickfuel 850 performed right out of the box have done nothing but change jets for weather conditions for over 6 years now best money spent..

As for gears my 416 ran 11.0's with 3.91's 4.30's should get you in the 10's no problem

 

[clinteg]

I'd say 850 cfm minimum on the carb. I run a Holley 950 HP and it got me in the 10's. With the nitrous, I don't think you'll have any issues achieving that.