Could I see any big increase by going with a bigger carb? Or do any of you have any track time difference with switching carbs? here is my specs
427-60 over.
215 oval ports (219/188)&ported /shaved
JE forged pistons 10.25-1 cr
UD hyd roller 288/296 234-242 .600 .600 on a 110 LSA. Matching springs
CC roller lifters
Crane 1.7 roller rockers
Cloyes hex adjust timing set
Performer RPM intake 1/2 four hole spacer
750 DP holley k&N air filter
Holley fuel pump
Mallory IGN
Dynomax headers
3''exhaust with flowmasters
Turbo 350 - 3000 b&m stall
410 12 bolt posi
3750 pounds with driver

I'd say the 750 is big enough.It should supply plenty of fuel with that pump and the right jetting...JMO

Thanks for the reply speedster
It just seems like it could take more cfm to me, because it seems to run out of air in the higher rpms. A friend of mine has a 1050 for sale I suppose that would be way to huge? is there anyone out there that has made a decent et improvment by going to a bigger carb?

There's no way to know unless you test it on your engine in your chassis. Set up the 750 first. @ 6800 a 427 wants around 800 cfm, so figure it based on where you're shifting. I would bet that a change to an 830 cfm annular carb or a 950HP would do ya good ET-wise. Or an 800 is one falls in your lap cheap. But you'd have to test that. Not a Dominator though.

I think if you keep the rpm's down (low 6k), the 750 should be fine.

I have the shift light set at 5800 but by the time it shifts its at 6000 to 6100 but its out of air at that point. It realy revs quick.

shouldnt need any more than 750 at 6000.

427*6100/3456=753.7cfm assuming 100% volumetric efficiency, but its prolly back at 90% or so, which would require even less!. It sure seems to me like it could use more like 800cfm considering most mild 350's work well with a 750, but that is what the formula says. I know Holley used to make an 800cfm spread bore with dual metering blocks, I think it was list # 6212, I don't know if they still make it. I think it needs more air, but 1050 seems like a bit much.

I agree with the lower rpm a 750DP SHOULD IN THEORY be enough. IMO I agree tune out and try and do wome work with the 750DP. If you can get access to a WBO2 or/and a dyno it would be ideal, but not a necessity. I have an 830 ann. model and I doubt it would be enough to really put you over the edge... you would be better paying a carb shop to modify yours for some extra flow. If you truely are running out on the top end I would go right to a 950 myself as it is basically a worked 850 and doesn't rate at a full 950 cfm.

Thank you for the replys.
I will see what I can do with my carb come spring. Or unless a bigger carb falls in my lap for a good price.

I ran 11.50's with a 468 and an old choke tower still there 750 DP.

I currently use an 850 box stock carb with Choke tower still there as well.

Now that's 125+ mph with 540" at 6000 RPM with an open plenum intake (For Now). It is still pulling hard at the top end with the $300 850 Carb.

I would say a bigger carb like a 1050 will Slow you down ET wise.

Just FYI here's a quick basic formula taken from Holley's website to calculate CFM requirements.

Engine size x the maximum RPM you plan to run/3456= CFM

350cu x 5800rpm divided by 3456= 587.@#$ So a 600cfm carb should do ya for this example...

Man I am sorry guys i just realized that I did not tell you the 427 is 60 over. I just made the edit on my combo. thanks for the formula
439 x 6100rpm divided by 3456 = 775cfm
or
439 x 6500rpm divided by 3456 = 826cfm
6500rpm if I dont start floating that is.
Thanks

You must also multply in the volumetric efficiency. I think most engines run at 90% VE. Multiply your total by .90 or .95.
826 (6500rpms) x .90 = 752.4 cfm