workin on my 300 six project and cant decide on a carb....

i already have the hooker headers and i'm planning on running true dual exhaust Cat delete with cutouts right at the header. so i can open them up on the freeway and when i wanna make some racket. when closed prolly going to dual thrush glasspacks with turndowns behind the cab.
planning on a offy C dual plane intake with obivious 4bbl carb
also evuntally going to install a Cam & lifter kit (Hydraulic Flat Tappet, Advertised Duration 268/268, Lift .456/.456)
also going to do a MSD coil with Mallory Distribtor and 8.2MM wires. already running Bosh platnum plugs (plus model i believe)
one day in the distant future i'll do a valve job but thats a long ways off if ever
a buddy oues me big time and is offering me one of three carbs, two are holly 650s and the other is a factory 4bbl on a HO 351W... it is not a boss winsor but he says its high output(never herda such)

all 3 carbs need to be rebuilt but are in decent conditon, which one would be best?

also is a High volume oil pump necessary? planning to tune for 5k RPM shift point at WOT
( http://www.summitracing.com/myaccoun...0-be5d8c91718c )-Summit Racing wishlist
and last but not least, what am i doing wrong? i'm sure there's something that i'm going about in the wrong manner or need to change or not doing at all ect ect ect... gimmie som output!

 

650 cfm is alot of carb for a 300 six. The 390 cfm is recommended and about right all the way up to about 4500 rpm. How many rpm's are planning on getting it up to?

 

planning to hit around 5000RPM, gonna be a daily driver pavement pounding machine

 

"offy C dual plane intake" ...an Offy C and Offy DP are two different manifolds.

You don't mention anything about head work, ie porting, larger than OEM valves, decking, c. chamber work, etc., so if that head is OEM, I'm thinking the Holley 390 would be about as large a carb as you would want. Or maybe an Autolite 4100 1.08 venturi (480 cfm), which Ford put on it's 289 'stangs.

I believe that larger than that would keep you in 'bogland'. If you go to Carburetor, Carburetors, Carbs, Carb Parts. Pony Carburetors - Your Ford Carburetor Restoration and Part Sales Specialist, and snoop around, they have a chart to help you calculate carb size for your engine.

 

I would think a 600 cfm would be plenty for a 300.

 

Let me put it this way: you can see all the mod's I have in/on my 300. My 500 Edelbrock is all it can handle.

 

Bigger carbs can be used but require adjustment of the secondaries to keep the from opening too much too fast OR a highly disciplined throttle foot...not mashing the gas too much too fast. An engine cannot be force fed with good results with a big carb.

 

Quadrajet. Cheap, cheap, and more cheap. Easy to build and tune.

 

Yup. Just make sure the throttle shafts are rebushed if needed when rebuilding.

Parts available here: Cliffs High Performance Quadrajets :: Quadrajet Rebuilding | Quadrajet Rebuild Kits, Carburetor Restoration, Bushing Kits and Parts

 

sorry meant the DP intake, C is single plane. and yes for now the head is OEM

 

With an oem head, I would say not to go larger than 400 cfm on the carb.

As I tried to say in my other posting, if you go to pony carbs website and dig around, they have a guide to calculate cfm for any engine.

Your selection will depend on research. Good luck.