Help me make up my mind...750 or 850 carb?

[s10aromeo]

I have a 427 sbc..690 lift solid roller.230 cc intake on my heads with 13.1 comp.I have changed my intake to a motown 4500 flange intake from my last season single plane 4150 flange.I made the mistake like many to big loses the torque I need to run the number.So to fix my problem I am going to step it down to a motown 4150 flange high rise single intake.Love those coolant cross overs.I found a carb calculator and it told me to run a 850 cfm carb.I have heared many bad things about the 850s and was told to use a 750.What does everyone think?

[Do-It-To-It]

i wouldnt run either . i love the holley h-p series carbs the 950 for a combo like yours thats what i run i most of the big compression, big cam, high flow heads i use down here. funny thing is they run great right outa the box they also have alot of goodies the 4781-850 and the 4779-750 dont come with.Notched floats and jet extensions for continuous fuel delivery
Center-hung floats offer plumbing on both sides
High-flow metering blocks
Nonstick, reusable metering block gaskets for easy tuning
Spun-in boosters won't fall into engine
Four corner idle system
Loctite-fastened buttonhead throttle plate screws for less air restriction
Viton-tipped needle and seats for precise fuel delivery
Stainless steel throttle plates for corrosion protection
High-strength sealing surfaces
Contoured Venturi inlet provides more balanced airflow, which increases power
Power valve blowout protection
100% wet-flow tested and calibrated
Changeable, screw-in air bleeds offer expanded tuning options
Dichromate finish

[mytmouz]

X2. I have the 950HP on my 428 small block and the motor LUVs it...

[s10aromeo]

X2. I have the 950HP on my 428 small block and the motor LUVs it...

what time does the motor put down?This is a drag race only app.So 950... over 850.only turning the motor to 7,000.Really think i need the 950?I am worried about going to big now since I have been there.

[s10aromeo]

just realized a 750 has the same runners as a 950 hp.Wow.durrrrrr...different base.. thats why my 1050 is killing my torque.

[Do-It-To-It]

that 950 is maybe even a little on the small side but youl be just fine with it youl prolly have to jet it up some fore sure wit the big in small block and all do a quartell mile pass then shut it down and check the plugs ya want to look dark tan to semi black a little and that should keep it from runnin lean

[mytmouz]

I run 6:16 in the 1/8 on motor. I want to try a 1000 hp...

[s10aromeo]

Thanks for the info guys.I am going to look into a bit more... I always trust this forms info.

[Highhat]

FYI - according to a telephone conversation I had with a Holley Tech, the 950HP only flows 790cfm.

[Do-It-To-It]

i had a fatory fresh outa the box 850 (4781) at the dyno and a 383 aluminum heads and a small rollor cam w/ 11.1 compression thing made 517 hp took the 950 hp outa the box and it made 542 hp whatever it flowed it worked way better than the 850 . and i jetted both carbs for max hp and torque

[mytmouz]

FYI - according to a telephone conversation I had with a Holley Tech, the 950HP only flows 790cfm.

Not chunking rocks here, but I replaced a worked 1050 Dom. with the 950 and the et's were nearly identical and I get about 3 x the passes per tankfull. The only thing I lost was the hard starting issues...

[PONY GUY]

you can alway run either a 850 or a 950 . The 850 would make the throttle more responsive or "snappy" outa the hole and if it feel like it needs more you can always play the the jetting

[adamsvega]

with one to one linkage and no choke horn you will loose alittle driveability .but what ever you do to better the airflow into and out of the center section wont hurt a thing .it is venturi size and booster restriction . that is the limits . i allways go with a annular booster in a over sized venturi in s/b apps. to get all i can every where .it allso makes it easy to tune !!!! a dominator on a s/b is mostly like a light switch! unless your big cube high rpm light car stick /brake racing your going to be quicker with the smaller high flow carb