Ive got the option to pick up a stock 351w 4 barrel intake with a holley 750 carb for $200. Im not too sure on what the carb actually is (double pumper/quadrajet ??) I should know tomorrow though.. The thing is, I was thinking that the 750 is going to be a little big for my mild 351 with hooker long tubes and a Edl. Performer cam. That and I have been planning on picking up a Weiand Stealth or an RPM manifold with a Edlebrock 600 or Holley street avenger 670 carb. Is the stock cast 4 barrel intake going to flow good enough to wake up my motor a bit more, or would I be better off just buying the new stuff? Only thing making me consider this sale is price. $200 is less than half of what I would pay for new components, but I want my motor to be matched efficently.. Carb to intake to cam to heads and headers.. I want it to breath the best that it can with what it has and retain a little gas mileage.

Im running the stock 2 barrel cast manifold with a autolite 2100d carb (if my memory serves me right).

 

I've used both 600 and 750 carbs on a mild 351W. I thought the 750 worked a litle bit better. But it was close. $200 for the carb (in good shape, ready to run) is not a bad deal. If the carb needs a rebuild, it's not such a good deal.

I wouldn't bother putting a stock cast iron manifold on, though. It will be better than what you have, but not significantly.

 

The guy who sold me my 302 has a 351W in his. He used the 750 on his and claimed he got better mileage after the swap. Our groups working theory is that it also flows more air hence the mileage increase. The manifold of choice across all the makes in our group is the Edelbrock Performer.

 

A 750cfm carb is too big for a 351 running NA. Unless you are using a blower or turbo, I would get a 650. Run a carburator calulator and you will see what I mean. You will not have enough VE to run that much carb. I have a 750 on my 383 with big lungs, and I am having problems atomizing fuel. A 383 calls for 760cfm at my rpm, but I tell you it is too much. I wish I had gone with a 700cfm, so I bet you will have hell tuning a 750 to run on your 351. Strange things happen when the fuel does not atomize correctly. Remember that over carbureting is a bad thing!

Intake...get an Edelbrock Air Gap. They kick ars!

 

the 200$ deal is great, but if you're actually going to do the work of pulling the intake and carb I'd rather buy (maybe even used) aluminum intake and carb size as the others suggest

 

650/670 is perfect, and throw that cast iron piece of crap intake into a lake somewhere. (well not really, but dont use it). performer rpm or airgap, or a stealth would be the route to go with

 

Thats good info,, I told the wife about the deal last night and she looked at me and said "Is it new?" and when I said no, she gave me the look like "well why buy it?" I will end up with a new RPM or Stealth intake and a 650cfm carb most likely.. I cant wait to get that top end opened up though..

So 650 should be about perfect you say?? and 750 a little too big? I have allways read that going a little smaller on the carb CFM is allways better..

 

IMHO, 650 is still to big for your application. i have a 480 cfm Autolite that's perfect. I would not go over 600. Also too. I believe the RPM manifold is for more top end power. If your cam is an off the line peice it won't match up very well. May want just the standard performer manifold. I would call edelbrock and get their input.

Good luck

 

ahhh the good old cfm debate again :-)
half the forum will tell you 600 is ok the other half will tell you 650 is ok ...

from what I've seen throyughout the years here seems to be:
600 will do but you might lack 10 HP when revving at 5500 ... which your engine will never see anyway but will give you better throttle response

 

Performer RPM (airgap or regular) with a Holley 600 vacuum secondary (I'm ot a big Edelbrock carb fan). If you are racing at sustained higher RPM, then a larger CFM carb, but for most it is too much.