I've got a 10.4:1 CR 406, fully ported Vic JR intake with AFR 210 heads. Pretty large cam, .602/.618 lift.

I've GOT a QF SS-850 carburetor that sprung a leak while driving today, had it towed home. Gas was coming somewhere from the front bowl. Its PROBABLY just the metering block gasket, or needle/seat or something easy, but being in Wisconsin I tucked it away in my garage covered for the year.

My question is, should I save up for a larger Carb over winter? What type of gains can I get from going 950 or 1050 on the 406? Considering having the Hooker LT Headers, two 3" collectors into a single 4" Mufflex exhaust.

I hear Driveability may suffer, what is meant by that? I've currently got 437 rwhp. In your experiences/knowledge, would a 950 or 1050 do much better or cause more harm than good?

 

Me personally would rebuild the carb you have, I just can't see you needing more carburetor than that on the street. That said, the only way to tell for sure is to swap out and put it on the clock.

 

What's your maximum RPM (red line shift point)?

 

5700 was my dyno peak power, my camshaft, intake & heads have the ability to be higher

 

General formula for calculating CFM requirements is cubic inch times the max RPM anticipated. Generally that's peak HP RPM plus a couple of hundred for overspeed. In your case call it 6000 RPM. Divide that answer by 3456.
704 CFM.
Stretch your RPM out to 6500 and the required CFM is 763.
This is figuring that you have 100% volumetric efficiency at or around peak (which is possible plus more).

 

I second just having yours rebuilt and running it.

 

Thanks for the input, ill probably save my $$ then for a new rearend. Not sure how much more my 10bolt can handle.

 

Don't feel bad....I'm running a 4th gen 10 bolt behind my twin turboed 355 with a tko 600......Only good thing is the rear end only has 18k on it.

 

Clean the needle seat bowl out and run it bigger gains you nothing

 

I would keep the 850. Clean it up really gasket it. I run a 800 on my 408sbc and it's not starving for fuel.

 

My friend and his brother both race 69 camaro's , with 427" BBC and his brother owns a machine shop so they get to try many intakes and carbs.
They stated the 850 double pumper was they ran on the strip dominator intake was the 2nd best for their application.

For 2 tenths quicker ET the 1050 dominator with adapter plate was the king.

They then said it is because the front tires stay on the ground with the 1050.
Big wheelies kill forward motion.

You can modify your current carb to flow more CFM if you need it.
But I am with you get a good rear end in it.
That is the first thing I always busted , I broke 4 of the gm 10 bolts in my Nova before I stuck a 9" into it.
1.5 years of driving my 57 and it too got a 9" as the rear end busted in it.

Not saying get a 9". It is just what I have on hand. Salvage yards are full of them and if you can weld.

 

I'm swapping in a Strange S60 rear end with 3:73 gears this Spring and shouldn't have to worry about it again.

 

That will do it.

 

If it pulls any vacuum at the top of the gears then there's a chance you can make more power with a larger carb, and/or better filter.